tma 2940 operator's manual - tke · 2020. 7. 19. · ta instruments tma 2940 1–3...

TA INSTRUMENTS TMA 2940 I

TMA 2940

Thermomechanical Analyzer

Operator’s Manual

PN 925615.001 Rev. D (Text and Binder)PN 925615.002 Rev. D (Text Only)Issued November 1999

TA Instruments

Thermal Analysis & Rheology

A SUBSIDIARY OF WATERS CORPORATION

TA INSTRUMENTS TMA 2940II

© 1995, 1996, 1997, 1999 by TA Instruments,Inc.109 Lukens DriveNew Castle, DE 19720

Notice

The material contained in this manual is be-lieved adequate for the intended use of thisinstrument. If the instrument or procedures areused for purposes other than those specifiedherein, confirmation of their validity andsuitability must be obtained from TA Instru-ments, Inc. Otherwise, TA Instruments does notguarantee results and assumes no obligation orliability. This publication is not a license tooperate under nor a recommendation to infringeupon any process patents.

TA Instruments TA Operating Software andInstrument, Data Analysis, and Utility Softwareand their associated manuals are proprietary andcopyrighted by TA Instruments, Inc. Purchasersare granted a license to use these softwareprograms on the instrument and controller withwhich they were purchased. These programsmay not be duplicated by the purchaser withoutthe prior written consent of TA Instruments.Each licensed program shall remain the exclu-sive property of TA Instruments, and no rightsor licenses are granted to the purchaser otherthan as specified.

TA INSTRUMENTS TMA 2940 III

Table of Contents

Notes, Cautions, and Warnings.................xi

Safety...........................................................xii

Instrument Symbols ...............................xii

Electrical Safety ...................................xiii

Handling Liquid Nitrogen ....................xiii

Lifting the Instrument ...........................xvi

Using This Manual...................................xvii

CHAPTER 1: Introducingthe TMA 2940............................................ 1-1

Introduction................................................. 1-3

Components .......................................... 1-3

The 2940 Instrument ................................... 1-5

2940 Display ........................................ 1-7

2940 Keypad ........................................ 1-7HEATER Switch .......................... 1-11POWER Switch .......................... 1-11

Accessories ............................................... 1-12

Standard Accessories ......................... 1-12

Optional Accessories .......................... 1-13

Specifications ............................................ 1-14

TA INSTRUMENTS TMA 2940IV

Table of Contents(continued)

CHAPTER 2: Installingthe TMA 2940............................................ 2-1

Unpacking/Repacking the TMA 2940 ........ 2-3

Unpacking the TMA ............................ 2-3

Removing the Shipping Material ......... 2-6

Repacking the 2940 .............................. 2-8

Installing the Instrument ............................. 2-9

Inspecting the System........................... 2-9

Choosing a Location .......................... 2-10

Installing the Thermocouple .............. 2-11

Installing the Weight Tray Door ........ 2-13

Installing the Stage ............................. 2-14

Installing the Expansion/Penetration Probes.............................. 2-18

Installing a Probe ......................... 2-18Removing a Probe........................ 2-19

Connecting Cables, Gas Lines,and Isolation Transformer .................. 2-20

GPIB Cable .................................. 2-20Purge Line.................................... 2-23Air Cool Line ............................... 2-25Power Cable ................................. 2-26Isolation Transformer .................. 2-27

TA INSTRUMENTS TMA 2940 V


Starting the 2940 ....................................... 2-29

Shutting Down the 2940 ........................... 2-31

CHAPTER 3: RunningExperiments............................................... 3-1

Overview ..................................................... 3-3

Before You Begin ................................ 3-4

Calibrating the TMA .................................. 3-5

Force Calibration .................................. 3-5

Probe Calibration ................................. 3-6

Temperature Calibration ...................... 3-7

Cell Constant ........................................ 3-9

Running a TMA Experiment .................... 3-10

Experimental Procedure ..................... 3-10

Selecting a Probe ................................ 3-11

Zeroing the Auto Measure System.....3-12

TA INSTRUMENTS TMA 2940VI


Sample Preparation and Loading ....... 3-13

Sample Preparation ...................... 3-13Sample Loading ........................... 3-13

Thermocouple Positioning ................. 3-15

Measuring theSample Length ................................... 3-15

Setting Up an Experiment .................. 3-16

Setting Up Accessories ...................... 3-17

Using Air Cool............................. 3-17Using a Purge Gas ....................... 3-18

Suggestions ........................... 3-18

Starting an Experiment ....................... 3-20

Stopping an Experiment ..................... 3-20

Removing Samples ...................... 3-20

Subambient Experiments .......................... 3-22

Performing a Cooling Experiment .....3-22

Techniques for ImprovedSubambient Operation........................ 3-23

TA INSTRUMENTS TMA 2940 VII


CHAPTER 4: UsingYour Options ............................................. 4-1

Overview ..................................................... 4-3

Film/Fiber Accessory .................................. 4-4

Description ........................................... 4-4

Operating Procedures ........................... 4-5

Accessory Installation .......................... 4-5

Removing the Existing Probe ........ 4-6Removing the Stage ....................... 4-6Changing the Instrument Mode ..... 4-7Installing the Film/Fiber Probe ..... 4-7Installing the Film/Fiber Stage ...... 4-8Calculating the Offset .................... 4-9

Calibration .......................................... 4-11

Sample Preparation ............................ 4-12

Using the Aluminum Balls .......... 4-12Using the StainlessSteel Clamps ................................ 4-14

Flexure Accessory .................................... 4-17

Description ......................................... 4-17

Accessory Installation ........................ 4-18

Calibration .......................................... 4-18


TA INSTRUMENTS TMA 2940VIII


Dilatometer Accessory.............................. 4-21

Description ......................................... 4-21

Operating Procedures ......................... 4-23

Considerations ............................. 4-23


Calibration .......................................... 4-24

Baseline Calibration .................... 4-24Displacement Calibration ............ 4-25


Parallel Plate Rheometer Accessory ......... 4-29

Description ......................................... 4-29


Calibration .......................................... 4-30


Sample Encapsulating Press ........ 4-31Preparing Moldable Powders ...... 4-35Preparing Resinous Materials ...... 4-38Preparing Sheet Materials............ 4-40

Sample Loading ................................. 4-41

Cleanup ........................................ 4-42

TA INSTRUMENTS TMA 2940 IX


Calculations ........................................ 4-43

Hemispherical Probe ................................. 4-47

CHAPTER 5: TechnicalReference................................................... 5-1

Description of the TMA 2940 ................... 5-3

Uses ofThermomechanical Analysis ................ 5-4

Calculating theCoefficient of Expansion ..................... 5-5

Method Considerations ............................... 5-6

Status Codes ............................................... 5-7

CHAPTER 6: Maintenanceand Diagnostics......................................... 6-1

Overview ..................................................... 6-3

Routine Maintenance .................................. 6-4

Inspection ............................................. 6-4

Cleaning ............................................... 6-5

Cleaning the Keypad ..................... 6-5Cleaning the Probe Assembly ........ 6-5Cleaning the Stage ......................... 6-6Cleaning the Thermocouple........... 6-7

TA INSTRUMENTS TMA 2940X


Replacements ....................................... 6-8

Installing a New Thermocouple .... 6-8

Diagnostics ................................................. 6-9

Fuses ..................................................... 6-9

Power Failures.................................... 6-10

TMA 2940 Test Functions........................ 6-12

The TMA Confidence Test ................ 6-12

Replacement Parts .................................... 6-15

APPENDIX A: OrderingInformation .............................................. A-1

INDEX ........................................................ I-1

TA INSTRUMENTS TMA 2940 XI

Notes, Cautions,and Warnings

This manual uses NOTES, CAUTIONS, andWARNINGS to emphasize important andcritical instructions under the guidelines de-scribed below:

Highlights important information about equipmentor procedures.

Emphasizes a procedure that may damageequipment or cause loss of data if not followedcorrectly.

Marks a procedure that may be hazardous tothe operator or to the environment if notfollowed correctly.

!WARNING

NOTE:

ttttt CAUTION:

TA INSTRUMENTS TMA 2940XII

Safety

Instrument Symbols

The following labels are displayed on the TMA2940 instrument for your protection:

Symbol Explanation

This symbol, whichappears on the furnaceenclosure and on the stagecan of the TMA 2940,indicates that a hotsurface may be present.Take care not to touchthese areas or allow anymaterial that may melt orburn to come in contactwith these hot surfaces.

Please heed the warning labels and take thenecessary precautions when dealing with thoseparts of the instrument. The TMA 2940Operator's Manual contains cautions andwarnings that must be followed for your ownsafety.

TA INSTRUMENTS TMA 2940 XIII

Electrical Safety

Voltages exceeding 110 Vac are present in thissystem. Always unplug the instrument beforeperforming any maintenance.

Because of the high voltages in this instru-ment, untrained personnel must not removethe cabinet cover unless specifically directedto do so in the manual. Maintenance andrepair of internal parts must be performed byTA Instruments, Inc. or other qualified servicepersonnel only.

After transport or storage in humid condi-tions, this equipment could fail to meet all thesafety requirements of the safety standardsindicated. Refer to the NOTE on page 2-11 forthe method of drying out the equipment beforeuse.

Handling Liquid Nitrogen

The TMA 2940 can use the cryogenic (low-temperature) agent, liquid nitrogen, for coolingin subambient experiments. Because of its lowtemperature (-195°C), liquid nitrogen will burnthe skin. Use extreme caution when workingwith liquid nitrogen and other cryogenic materi-als to ensure that you do not burn yourself.

Personnel working with liquid nitrogen shouldtake the following precautions.

Liquid nitrogen evaporates rapidly at roomtemperature. Be certain that areas whereliquid nitrogen is used are well ventilated toprevent depletion of oxygen in the air.

!WARNING

!WARNING

!WARNING

TA INSTRUMENTS TMA 2940XIV

1. Wear goggles or a face shield, gloves thatare large enough to be removed easily, and arubber apron. For extra protection, wearhigh-topped, sturdy shoes, and leave yourpant legs outside the shoe tops.

2. Transfer the liquid slowly to prevent thermalshock.

3. Use containers having adequate low-temperature properties. Ensure that closedcontainers have vents to relieve pressure;liquid nitrogen evaporates rapidly at roomtemperature.

4. The purity of liquid nitrogen alters as itevaporates. If much of the liquid in thecontainer has evaporated, check the remain-ing liquid before using it for any purpose inwhich high oxygen content is dangerous.

IF BURNED BY LIQUID NITROGEN...

1. Flood the area (skin or eyes) with largequantities of cool water IMMEDIATELY;then apply cold compresses.

2. See a doctor IMMEDIATELY if the skin isblistered or if there is a chance of eyeinfection.

TA INSTRUMENTS TMA 2940 XV

Potential Asphyxiant

Liquid nitrogen can cause rapid suffocation withoutwarning.

Store and use in an area with adequate ventilation.

Do not vent LNCA container in confined spaces.

Do not enter confined spaces where nitrogen gasmay be present unless the area is well ventilated.

The warning above applies to the use of liquid nitrogen. Oxygendepletion sensors are sometimes utilized where liquid nitrogen isin use. Please refer to the “Safety” section of the TA Instru-ments Liquid Nitrogen Cooling Accessory manual for more de-tailed instructions regarding the use of the LNCA.

!WARNING

TA INSTRUMENTS TMA 2940XVI

Lifting the Instrument

The TMA 2940 is a fairly heavy instrument. Inorder to avoid injury, particularly to the back,please follow this advice:

Use two people to lift and/or carry theinstrument. The instrument is too heavy forone person to handle safely.

!WARNING

TA INSTRUMENTS TMA 2940 XVII

Using This ManualCHAPTER 1 Introduces the TMA 2940

and lists its specifications.

CHAPTER 2 Describes how to installand assemble your TMA2940.

CHAPTER 3 Describes routine opera-tion of the TMA instru-ment, including subambi-ent operations.

CHAPTER 4 Contains the proceduresused to operate the TMAwith the optional accesso-ries.

CHAPTER 5 Explains the technicalaspects of the TMA andits operation.

CHAPTER 6 Provides maintenance anddiagnostic procedures.

Appendix A Lists TA Instrumentsoffices that you cancontact to place orders,receive technical assis-tance, and request service.

Index Contains an alphabeticallist of topics and pagenumber references.

TA INSTRUMENTS TMA 2940XVIII

TA INSTRUMENTS TMA 2940 1–1

CHAPTER 1: Introducing theTMA 2940

Introduction................................................. 1-3

Components .......................................... 1-3

The 2940 Instrument ................................... 1-5

2940 Display ........................................ 1-7

2940 Keypad ........................................ 1-7HEATER Switch .......................... 1-11POWER Switch .......................... 1-11

Accessories ............................................... 1-12

Standard Accessories ......................... 1-12

Optional Accessories .......................... 1-13

Specifications ............................................ 1-14

Introduction

1–2 TA INSTRUMENTS TMA 2940


IntroductionThe Thermomechanical Analyzer (TMA) 2940is an analytical instrument used to test thephysical properties of many different materials.

The TMA 2940 works in conjunction with a TAInstruments controller and associated softwareto make up a themal analysis system.

Your controller is a computer that performs thefollowing functions:

• Provides an interface between you and theanalysis instruments

• Enables you to set up experiments andenter constants

• Stores experimental data• Runs data analysis programs.

Components

Your instrument consists of two major parts, theTMA cabinet and the TMA assembly (seeFigure 1.1 on the next page). The followingcomponents make up the TMA assembly:

• The balance enclosure surrounds the TMAbalance mechanism which exerts a specifiedforce on the sample.

• The probe assembly is interchangeable formaking several different measurements onvarious sample materials.

• The stage is an interchangeable componentthat supports the sample duringmeasurement.

Introduction

Introduction


• The furnace assembly surrounds the stage toheat the sample; it contains the integralcooling container and the furnace monitorthermocouple.

• The weight tray, located behind the weighttray door, holds the weights to exert aknown force on the sample.

• The Chromel/Alumel sample thermocouplesenses the temperature of the sample andrelays the reading to the instrument.

Figure 1.1The TMA 2940Instrument

InstrumentDisplay

InstrumentKeypadFurnace

Enclosure

BalanceEnclosure

Cabinet


The 2940 InstrumentThe TMA 2940 instrument contains the elec-tronics and software needed to perform experi-ments and store the results. The battery backed-up memory in the cabinet saves parameters vitalto system operations if power is interrupted.Also contained in the cabinet is a GPIB interfacefor communication with the controller.

You can set up, start, stop, and reject the experi-ment using the keypad on the cabinet. Thedisplay provides valuable realtime informationon the experiment in progress.

The TMA was developed by TA Instrumentswith the following features:

• operates over a temperature range of -150oCto 1000oC using heating rates up to200oC/min

• determines changes in sample propertiesresulting from changes in four experimentalvariables: temperature, force, atmosphere,and time

• uses samples that can be in solid, film, fiber,or powder form

• employs interchangeable probes allowingyou to measure the melting point, softeningpoint, tensile modulus, compressionmodulus, glass transition, stress relaxation,creep, and expansion coefficient

The 2940 Instrument

Introduction


• allows additional experiments in parallelplate rheometry, fiber tension, shrinkageforce, flexure, and dilatometry with theoptional accessories that can be used withthe instrument.

The cabinet contains the keypad, used to controlthe mechanical movements of the instrument,and the display, used to observe the status of theinstrument.

Figure 1.2TMA 2940Keypad and Display

TMA 2940 Thermomechanical Analyzer

Standby 23.25°CDimChg 0.135µm


2940 Display

The TMA display is the lighted area of thekeypad unit (see Figure 1.2). It contains tworows of 20 characters each.

During normal operation, the display is dividedinto three areas:

• Method status display—the eight-characterline on the top left

• Sample temperature display—the ninecharacters on top right

• Realtime signal display—the whole bottomline.

2940 Keypad

The instrument keypad (Figure 1.2) contains thekeys found in Table 1.1 on the next page and theHEATER and POWER switches.

Experiment and instrument constants are enteredfrom the controller keyboard, not the instrumentkeypad.

The 2940 Instrument

NOTE:

Introduction


Table 1.1TMA 2940Keypad Functions

Key/Function Explanation

SCROLL Scrolls the realtimesignals shown on thebottom line of the display.

ZERO Initializes the auto-LENGTH measure system. This

operation should beperformed any time theprobe or stage is changed.

MEASURE Measures your sample’s LENGTH length automatically;

use this key beforebeginning the run. Themeasured length istransferred to the Experi-mental Parameterswindow and the value isrecorded in the SampleSize field.

PROBE ▲ Used to “open” the probe,this key raises the probe 3mm, the range of theLVDT, when pressed onetime. When the key ispressed a second time,mechanical action occurs,moving the probe andLVDT coil to theirmaximum upward posi-tion.

(table continued)


The 2940 Instrument

Table 1.1(continued)


If the probe is movingdown and Probe ▲ ispushed, the probe willstop and reverse itsdirection.

PROBE ▼ Used to “close” the probe,this key lowers the probe3 mm, the range of theLVDT, when pressed onetime. When the key ispressed a second time,mechanical action occurs,centering the LVDT coil.

If the probe is moving upand Probe ▼ is pushed,the probe will stop andreverse its direction.

▲ Raises or lowers theFURNACE furnace. You can stop

▼ the furnace movement bypressing this key asecond time. If you pressthe key twice while thefurnace is moving, youcan halt and reverse themovement.

START Initiates the experimenton the TMA after check-ing the program methodagainst the mode type.This is the same functionas Start on the controller.

(table continued)

Introduction


Table 1.1TMA 2940 KeypadFunctions(continued)


STOP If an experiment isrunning, this key ends themethod normally, asthough it had run tocompletion; i.e., themethod-end conditionsgo into effect and the datathat has been generated issaved. This is the samefunction as Stop on thecontroller.

If an experiment is notrunning (the instrument isin a stand-by or method-end state), the STOP keywill halt any activity (aircool, all mechanicalmotion, etc.).

REJECT If an experiment isrunning, SCROLL-STOPends the method normal-

(Hold down ly, as though it had run toSCROLL and completion; i.e., thepress STOP) method-end conditions go

into effect and the datathat has been generated isdiscarded. This is thesame function as Rejecton the controller.

(table continued)


The 2940 Instrument

NOTE:



SCROLL operates normally(scrolls the text) until theSTOP key is pressed. Thenthe display returns to thesignal displayed on thescreen before SCROLLwas pressed.

If an experiment is notrunning, SCROLL-STOPhalts any activity asdescribed for the STOPkey.

HEATER Switch

The HEATER on/off switch turns the power tothe instrument heater on and off (see Figure1.2). The switch should be in the ON positionbefore you start an experiment. If the HEATERswitch is off, the run will not start.

The light in the HEATER switch will glow only whenan experiment is in progress or when the tempera-ture is being controlled by a method-end condition.

POWER Switch

The POWER on/off switch turns the power tothe instrument on and off (see Figure 1.2).

NOTE:

Introduction


AccessoriesThe TMA 2940 can perform experiments onseveral different types of samples using bothstandard and optional accessories.

Standard Accessories

The accessory kit supplied with the TMA 2940contains weights, sample holder (stage), a hexwrench, tweezers, samples for calibration, andstandard probes.

The standard probes (see Figure 1.3) allow youto perform various basic analyses. These probesinclude the following:

• The expansion probes are used to measurethe thermal coefficient of expansion andglass transition. The standard expansionprobe is used for routine samples. Themacro expansion probe covers a larger areaof the sample surface and is therefore ableto give a more representative reading forsamples such as powders, materials withuneven surfaces, frozen liquids, and films.

• The penetration probe has a small tip thatpermits it to sink into the material as it isheated, and is used to measure softening andmelting points.


Figure 1.3TMA Standard Probes

Optional Accessories

You can purchase extra items to use with yourTA Instruments TMA. These optional accesso-ries will allow you to perform experiments ondifferent types of samples:

• Film/Fiber Accessory• Dilatometer Accessory• Parallel Plate Rheometer Accessory• Flexure Accessory• Hemispherical Probe.

Turn to Chapter 4, “Using Your Options,” fordetails on the installation and operation of theseaccessory kits.

Accessories

Introduction


SpecificationsTables 1.2 and 1.3 contain information about theTMA’s specifications and temperature control.

Table 1.2TMA 2940InstrumentSpecifications

Dimensions Depth 45.5 cm (18 in.)Width 58.5 cm (23 in.)Height 66 cm (26 in.)

Weight (approx.) 18 kg (60 lb)

Power 115 V ac 50/60 Hz10 amps

Temperature -150 to 1000oCRange

Sample Height 25 mm (1 inch)maximum

Sample Diameter 10 mm (0.39 inch)maximum

Sensitivity 100 nanometers

Displacement +2.5 mmRange (+0.10 inch)

Linearity +0.5%

Loading 0.001 to 1.0 Newtons(102 grams)

Atmosphere Static or controlled flowwith inert or reactivegases.


Table 1.3Temperature Control

Programmed 0.01 to 200oC/minheating rate

Temperature +2oCreproducibility

Specifications

Introduction



CHAPTER 2: Installing theTMA 2940

Unpacking/Repacking the TMA 2940 ........ 2-3

Unpacking the TMA ............................ 2-3

Removing the Shipping Material ......... 2-6

Repacking the 2940 .............................. 2-8

Installing the Instrument ............................. 2-9

Inspecting the System........................... 2-9

Choosing a Location .......................... 2-10

Installing the Thermocouple .............. 2-11

Installing the Weight Tray Door ........ 2-13

Installing the Stage ............................. 2-14

Installing the Expansion/Penetration Probes .............................. 2-18

Installing a Probe ......................... 2-18Removing a Probe ........................ 2-19

Connecting Cables, Gas Lines,and Isolation Transformer .................. 2-20

GPIB Cable .................................. 2-20Purge Line .................................... 2-23Air Cool Line ............................... 2-25Power Cable ................................. 2-26Isolation Transformer .................. 2-27

Starting the 2940 ....................................... 2-29

Shutting Down the 2940 ........................... 2-31

Installation

TA INSTRUMENTS TMA 29402–2


Unpacking/Repackingthe 2940

These instructions are also found as separateunpacking instructions in the shipping box.

You may wish to retain all of the shippinghardware, the plywood, and boxes from theinstrument in the event you wish to repack andship your instrument.

Unpacking the TMA

Refer to Figures 2.1 to 2.3 while unpacking yourinstrument.

Have an assistant help you unpack this unit.Do not attempt to do this alone.

Figure 2.1Shipping Boxes

Unpacking the TMA

NOTE:

!WARNING

Installation


1. Open the shipping carton and remove theaccessory box.

2. Remove the cardboard packing insert.

3. Stand at one end of the box with yourassistant facing you at the other end. Liftyour end of the unit out of the box as yourassistant lifts his/her end.

4. Place the unit on a lab bench with one sidehanging over the edge of the bench (seeFigure 2.2). Someone must be holdingonto the unit at all times while it is in thisposition.

Figure 2.2Removing thePlywood Board

5. While your assistant holds the unit, use awrench to remove the two nuts and washersfrom the bottom. Then lift and rotate theunit so that the other end hangs over theedge of the bench. Someone must holdonto the unit at all times while it is in thisposition. While your assistant holds theunit, remove the two nuts and washers fromthe other side.


6. Slide the unit completely onto the lab bench.Have your assistant hold one side up whileyou unscrew and remove the black rubbervibration mounts from the bottom. Thenrotate the unit and remove the vibrationmounts from the other side in the samemanner.

7. Remove the ¼ x 20 screws and mountingfeet from the accessory kit. Place the screwthrough the center of the rubber feet.

8. Have your assistant lift the entire unit whileyou slide the plywood board out from underit.

9. Have your assistant lift one side of the unitwhile you install two of the mounting feet(see Figure 2.3). Rotate the unit and installthe two remaining mounting feet in the samemanner.

Figure 2.3 Installingthe Mounting Feet

Unpacking the TMA

Installation


Removing theShipping Material

The TMA 2940 has been specially packed toprevent damage to delicate parts. To unpack theinstrument follow these steps:

Steps 1-9 may be completed by the customer.Only qualified service personnel should proceedwith steps 10-19.

1. Unscrew the black cap on the furnace post.

2. Slip off the cardboard cylinder, then replacethe cap on the furnace post.

3. Raise the furnace and rotate it clockwise tomove it off to the side.

4. Take the stage shield off and discard thepacking foam.

5. Unscrew the large nut to remove.

6. Twist the stage retainer ring (with key slots)counter-clockwise and pull it up off thethree posts.

7. Remove the shipping foam inside.

8. Get the hex wrench out of the accessory kitand remove the screws, two on each side,that hold the balance enclosure in place.

9. Slide the balance enclosure out and remove(see Figure 2.4).

ttttt CAUTION:


Whenever you remove the balance enclosure,make sure that the power is off and theinstrument is unplugged.

Figure 2.4Removing theBalance Enclosure

Only qualified service personnel should proceedbeyond this point.

10. Using a 7/64" hex wrench, loosen andcarefully remove the top and bottom clamp-ing bars of the suspension shipping clamp.

11. Using the same wrench, remove the eight (8)screws from the front and rear clamping barsof the suspension shipping clamp. Carefullyslide the clamping bars horizontally left orright to remove them.

12. Inspect the suspension components (wiresand springs) for damage.

13. Remove the shipping foam at the rear of thebalance assembly by pulling upward.

Unpacking the TMA

!WARNING

ttttt CAUTION:

Installation


14. Locate the black plastic weight tray and 4-40 nylon screw which were packed in thetop of the furnace. Using the nylon screw,install the weight tray into the front openingof the balance housing.

15. Verify the mechanical balance of thesuspension assembly. Adjust if necessaryby fine-tuning the positions of the weights.

16. Continue with installation of the thermo-couple found on page 2-11.

17. Reinstall the balance enclosure and tightenthe four screws.

18. Plug in and turn on the power to the TMAinstrument. Allow it to warm up for at least30 minutes.

19. Check the force calibration (see the instru-ment control online documentation fordetails).

Repacking the 2940

To pack and ship your instrument, use thehardware retained during unpacking and reversethe instructions found on pages 2-3 to 2-8.


Installingthe Instrument

Before shipment the TMA 2940 instrument isinspected both electrically and mechanically, sothat it is ready for operation after it has beeninstalled. Installation involves the followingprocedures described in detail in this chapter:

• Unpacking the instrument components andaccessory kit

• Inspecting the system for shipping damageand missing parts

• Assembling the TMA• Connecting the TMA to the TA Instruments

controller• Connecting the purge gas and air line,

accessories, and power cable.

If you wish to have your instrument installed bya TA Instruments Service Representative, call(302) 427-4000 for an installation appointmentwhen you receive your instrument.

To avoid mistakes, read this entire chapterbefore you begin installation.

Inspectingthe System

When you receive your TMA, look over theinstrument and shipping container carefully forsigns of shipping damage and check the partsreceived against the enclosed shipping list.

If the instrument is damaged, notify the carrierand TA Instruments immediately.

Installing the Instrument

ttttt CAUTION:

Installation


If the instrument is intact but parts are missing,contact TA Instruments.

A list of TA Instruments offices can be found inAppendix A of this manual.

Choosinga Location

Because of the sensitivity of TMA experiments,it is important to choose a location for theinstrument using the following guidelines:

In . . . a temperature-controlled area.. . . a clean environment.. . . an area with ample working and

ventilation space around the instru-ment. (Refer to the technical speci-fications in Chapter 1 for the instru-ment’s dimensions.)

On . . . a stable, vibration-free work surface.

Near . . . a power outlet (115 Vac, 50 or 60 Hz,10 amps). A step up/down line trans-former may be required if the unit isoperated from a higher or lower linevoltage.

. . . your TA Instruments thermal analysiscontroller.

. . . sources of compressed lab air andpurge gas supply for use duringcooling and subambient experiments.

Awayfrom. . . dusty environments.

. . . exposure to direct sunlight.

. . . direct air drafts (fans, room air ducts).

. . . poorly ventilated areas.


Drying out the instrument may be needed, if it hasbeen exposed to humid conditions. Certain ceramicmaterials used in this equipment may absorbmoisure, causing leakage currents to exceed thosespecified in the applicable standards (see page xiii)until the moisture is eliminated. It is important tobe certain that the instrument ground is ad-equately connected to the facilities ground for safeoperation.

Run the following method to dry out the instrument(refer to “Running Experiments” for further infor-mation).

1 Ramp at 10°C/min to 400°C2 Isothermal for 30 min.

Installing theThermocouple

Your TMA 2940 will arrive without a samplethermocouple installed. With the balanceenclosure removed and the furnace raised,follow these steps:

1. Insert the two-pin, color-coded thermo-couple connector into the fitting as shown inFigure 2.5.

Figure 2.5Plugging inthe Thermocouple


NOTE:

Installation


2. Carefully thread the thermocouple, tip first,up through the hole in the top of the balanceenclosure. (See Figure 2.6.)

Figure 2.6Threading theThermocouple

3. Move the thermocouple off to the side of thestage platform.

4. Route the thermocouple wire through thewire guide to prevent interference with thebalance mechanism.

5. Slide the balance enclosure into position.

6. Replace the screws, two on each side, thathold the balance enclosure in place.

7. Install the weight tray door as instructed inthe next section.


Installing theWeight Tray Door

Locate the plastic weight tray door in the boxwith the accessory kit, wrapped in a sheet ofshipping material. Remove the shipping mate-rial and follow these steps to install the door:

1. Locate the mounting holes on the top andbottom of the door.

2. Hold the door with these mounting holes tothe left.

3. Put the lower hole over the small bottompost to the left of the weight tray.

4. Push down gently on the door as you guidethe upper hole over the cone-shaped post atthe top of the entrance.

5. Release the door and close it.

6. Install the stage as directed in the nextsection.


Installation


Installing the Stage

To install the stage on the TMA 2940, check tomake sure the furnace is raised and off to theside, then follow these steps (refer to Figure 2.7for illustration of the parts):

1. Remove the stage shield by lifting it straightup. (This is a friction fit.)

2. Turn the large stage nut counterclockwise toremove it.

3. Twist the stage retainer ring (with key slots)counterclockwise and pull it up off the threeposts.

4. Remove the stage from the accessory kit.

5. Slide the wave washer (rippled edge washer)down over the top of the stage so that it fitson the flange.

6. Slide the stage retainer ring down over thetop of the stage so that it rests on top of thewave washer.

7. Insert the whole assembly (stage, wavewasher, and retainer ring) into the stageopening, lining up the key slots in theretainer ring with the posts.

8. Press down and turn the retainer ringclockwise to lock the assembly in position.

9. Replace the large stage nut, turning itclockwise to install it.


Figure 2.7Exploded Viewof TMA Stage Assembly

10. Attach the thermocouple to the stage asfollows:

a. Position the tip of the thermocouple sothat it bends at a 90°angle and lies flat againstthe platform. It should beclose to, but not touchingthe sample.

b. Hold the thermocouple against the stageassembly and put on the spring clip tohold the thermocouple in place (seeFigure 2.8).


Installation


Figure 2.8Attaching theThermocoupleto the Stage

11. Put the stage shield on the stage, aligningthe slot in the bottom over the thermocouplewires (see Figure 2.9).

12. Rotate the furnace into position over thestage.

SPRING CLIP


Figure 2.9Assembled TMAwith Stage andThermocouple

13. Install one of the probes as directed in thenext section. (Refer to Chapter 3 forguidelines in selecting a probe.)


Stage Shield

ThermocoupleWires

Installation


Installing theExpansion/Penetration Probes

When you first receive the TMA 2940, a probewill need to be installed. Later, if a differentsample form is used, you can change to theappropriate probe for the experiment. (Refer toChapter 3 for details on probe selection.) Theprocedures that follow explain the installationand removal of the expansion, macro expansion,penetration, flexure, dilatometer, and hemi-spherical probes.

To learn how to install the film/fiber probe, turn toChapter 4, "Using Your Options."

Installing a Probe


2. Insert the core end of the probe carefullyinto the opening in the TMA stage (seeFigure 2.10).

3. Loosen the probe-locking lever, which is theknurled post found behind the weight traydoor, by turning it counterclockwise. Holdthe probe-locking lever in the up positionand continue lowering the probe into thestage until you can feel it seat in the lockingmechanism.

NOTE:


Figure 2.10Installing the Probe

4. Tighten the probe-locking lever by turning itclockwise.

5. Calibrate the newly installed probe asdirected in Chapter 3, “Running Experi-ments.”

Removing a Probe1. Raise the furnace and rotate it clockwise to

move it off to the side.

2. Grasp the top of the probe with one hand.Using the other hand, locate and hold theprobe-locking lever, found behind the doorthat covers the weight tray.

3. Unscrew the locking lever by turning itcounterclockwise approximately one turn.

4. Raise the probe gently and twist slightly toaid its removal from the stage opening.


Installation


Connecting Cables, Gas Lines,and Isolation Transformer

In order to connect the cables and gas lines, youwill need to have access to the instrument’s rearpanel.*

* All directional descriptions for this sectionare written on the assumption that you arefacing the back of the instrument.

Connect all cables before connecting the powercords to outlets. Tighten the thumbscrews on allcomputer cables.

When plugging or unplugging power cords,always handle them by the plugs, not by thecords.

Protect power and communications cablepaths. Do not create tripping hazards bylaying them across accessways.

GPIB Cable

1. Locate the GPIB connector on the right rearof the instrument (see Figure 2.11).

2. Connect the GPIB cable to the GPIB con-nector. The GPIB cable is the only cablethat fits into this connector.

3. Tighten the hold-down screws on theconnector.

4. Connect the other end of the GPIB cable tothe controller or to the GPIB cable ofanother TA Instruments instrument con-nected to the controller.

NOTE:

!WARNING

ttttt CAUTION:

NOTE:


Figure 2.11TMA Connector Panel

5. Select an address from 1 to 9. Use thebinary address switches on the TMAconnector panel to set the desired address(see Table 2.1). Figure 2.12 shows a instru-ment address of 7.

If you have a multiple instruments system, eachinstrument must have a different address.

NOTE:


Installation


ADDRESS1 2 3 4 5O

N

If you change the address after the TMA ispowered on, you must press the TMA Resetbutton to enter the new address. Wait 30seconds after releasing the Reset button, thegreen Ready light should begin to glow steadily.Reconfigure the instrument with the controllerto bring the instrument back online.

Figure 2.12Binary Address Switches

Table 2.1Binary Address Settings

Address Switch Pattern

1 2 3 4 51 0 0 0 0 12 0 0 0 1 03 0 0 0 1 14 0 0 1 0 05 0 0 1 0 16 0 0 1 1 07 0 0 1 1 18 0 1 0 0 1

* 0 = OFF; 1 = ON


Purge Line

1. Locate the PURGE fittings on the right sideof the TMA instrument (see Figure 2.13).

Figure 2.13Purge Fitting

Use of an explosive gas as a purge gas isdangerous and is not recommended forthe TMA instrument. For a list of thegases that can be used in the TMA, seeChapter 3.

Use of corrosive gases will shorten the life of theinstrument.

2. Make sure that the pressure of your purgesource does not exceed the manufacturer'srecommended pressures for flowmeters andother regulated devices you are using.

The purge gas flows through the instrumentand is channeled internally to the samplepurge line shown in the figure on the nextpage.

!WARNING

ttttt CAUTION:


Installation


3. Connect a length of 6.2-mm (1/4-inch) I.D.flexible tubing from the PURGE fitting to aflowmeter (consult your compressed gasvendor for specific requirements). Thenconnect the flowmeter to the purge gassource.

4. The recommended setting for the purge rateis 100 mL per minute (–100°C and above)and 200 mL/minute (–150°C and above).

Figure 2.14Air Cool andSample Purge Lines


Air Cool Line

1. Locate the COOLING GAS fitting, a 6.2-mm (1/4-inch) compression fitting on theleft side of the TMA cabinet back, markedwith a maximum pressure warning label(840 kPa [120 psi]), as seen in the figurebelow.

Figure 2.15TMA COOLINGGAS Fitting

2. Make sure your compressed lab air source isdry, filtered, and regulated to between 175kPa (25 psi) and 840 kPa (120 psi).

3. Connect a compressed air line to the COOL-ING GAS fitting.


Installation


Power Cable

Connect all other cables and gas lines beforeconnecting the power cable to a wall outlet.

1. Make sure the instrument POWER switch(see Figure 2.16) is in the OFF (O) position.

Figure 2.16Front Panel of TMAShowing POWER Switch

2. Plug the power cable into the TMA.

Before plugging the TMA power cable into thewall outlet, make sure the instrument is compat-ible with the line voltage. Check the label on theback of the unit to verify the voltage.

3. Plug the power cable into the wall outlet.

NOTE:

ttttt CAUTION:



Isolation Transformer

The isolation transformer prevents any heaterleakage current from reaching the instrumentground circuit. To eliminate a potential shockhazard, do not operate the TMA with theisolation transformer disconnected.

The isolation transformer must be connected tothe back of your TMA. The number of cablesthat must be connected in sequence will dependupon the configuration of the connectors on theback of the module. All necessary cables will beprovided, however, you may not need to usethem all.

1. Place the isolation transformer near theheater power connections on the rear of theTMA cabinet.

2. Connect the isolation transformer to theheater power connections utilizing theappropriate cables provided. These cablesaccommodate different versions of thetransformer and TMA cabinet and can onlybe connected one way for each combination.See the illustration on the next page.

!WARNING


Installation


Figure 2.17Isolation TransformerCable Connections


Starting the 2940Allow the TMA to warm up for at least 30 minutesbefore performing an experiment.

1. Check all connections between the TMAand the controller. Make sure each compo-nent is plugged into the correct connector, asdescribed in this chapter.

2. Turn the instrument POWER switch to theON ( ) position. The instrument will run aninternal confidence test each time you turnon the power.

3. Watch the instrument display during theconfidence test for any messages that maybe indicated. Confidence test definitions aregiven in Chapter 6.

After the confidence test has finished, the screenwill briefly display the system status, indicatingthe amount of data storage memory availableand the GBIP address. Next follows the copy-right display, and then the standby display,shown in the figure on the next page.

4. Bring the instrument online with the TAcontroller.

NOTE:

Starting the 2940

Installation



Standby 23.25°CDimChg 0.135µm

Figure 2.18TMA StandbyDisplay


Shutting Downthe 2940

Turning the system and its components on andoff frequently is discouraged. When you finishrunning an experiment on your instrument andwish to use the thermal analysis system for someother task, leave the instrument on; it will notinterfere with whatever else you wish to do.

If your system will not be used for longer than 5days, we suggest that you turn it off. To powerdown your instrument for any reason, simplypress the POWER and HEATER switches to theOFF (0) position.

Shuting Down the 2940

Installation



CHAPTER 3: Running Experiments

Overview ..................................................... 3-3

Before You Begin ................................ 3-4

Calibrating the TMA .................................. 3-5

Force Calibration .................................. 3-5

Probe Calibration ................................. 3-6

Temperature Calibration ...................... 3-7

Cell Constant ........................................ 3-9

Running a TMA Experiment .................... 3-10

Experimental Procedure ..................... 3-10

Selecting a Probe ................................ 3-11

Zeroing the Auto Measure System.....3-12

Sample Preparation and Loading ....... 3-13

Sample Preparation ...................... 3-13Sample Loading ........................... 3-13

Thermocouple Positioning ................. 3-15

Measuring theSample Length ................................... 3-15

Setting Up an Experiment .................. 3-16

Running Experiments


Setting Up Accessories ...................... 3-17

Using Air Cool............................. 3-17Using a Purge Gas ....................... 3-18

Suggestions ........................... 3-18

Starting an Experiment ....................... 3-20

Stopping an Experiment ..................... 3-20

Removing Samples ...................... 3-20

Subambient Experiments .......................... 3-22

Performing a Cooling Experiment .....3-22

Techniques for ImprovedSubambient Operation........................ 3-23


OverviewAll of your TMA experiments will have thefollowing general outline. In some cases, not allof these steps will be performed.

� Selecting and calibrating the appropriateprobe type

� Entering experiment information throughthe TA controller (sample and instrumentinformation)

� Creating and loading the thermal method onthe controller

� Attaching and setting up externalaccessories as required (e.g., purge gas, aircool, gas switching accessory)

� Zeroing the probe

� Preparing and loading the sample

� Adjusting the thermocouple position

� Measuring sample length

� Adding coolant to the furnace reservoir forsubambient operation.

� Starting the experiment.

To obtain accurate results, follow the procedurescarefully and check calibration periodically(once a month). Consult the online documenta-tion for details on calibrating the TMA.

Overview

Running Experiments


Before You Begin

Before you set up an experiment, ensure that theTMA and the TA controller have been installedproperly. Make sure you have:

• Made all necessary cable connectionsbetween the TMA and the TA controller

• Connected all gas lines• Powered on each unit• Installed all appropriate options• Configured the instrument online with the

TA controller• Become familiar with controller operations• Changed the instrument mode, if necessary• Calibrated the instrument, if necessary.


Calibrating the TMATo keep your TMA 2940 working to the highestlevel of performance possible, it is importantthat certain calibrations be performed on theinstrument. Some procedures will need to bedone on a regular basis and others only occa-sionally.

Please note that this chapter provides guidelineson when to perform these calibrations, for detailson how to perform each calibration procedure,refer to the Thermal Solutions/Advantage UserReference Guide or to the online documentation.

Force Calibration

Force calibration calibrates the force exerted bythe probe on the sample during experimentsusing two weights and can be performed withany probe in place on the instrument. The firstcalibration point is 0 grams. It is suggested thatthe second calibration be performed with a 50gram weight. You may use weights other than50 grams (up to 100 grams is allowable). Forexample, you can use 10 grams for force calibra-tion, if only low forces will be used in subse-quent experiments.

When to Calibrate:

Perform the force calibration procedure in thefollowing situations:

� When you first receive the instrument

� When you change software

� Periodically (approximately once a month).

Calibrating the TMA

NOTE:

Running Experiments


A force calibration performs the functions ofa probe calibration (see the next section). There-fore, it is not necessary to perform a probecalibration immediately following a force calibration.

Probe Calibration

This procedure, sometimes called “initializing,”is used to calibrate zero force, the LVDT and theprobe's compliance. This corrects for anydifference in the different probes used on theTMA 2940 and should be done every time youchange the instrument mode or when you changea probe on the TMA 2940. This calibration isperformed from the TA controller.

NOTE:


Calibrating the TMA

Temperature Calibration

Temperature calibration is based on a run inwhich a temperature standard (e.g., indium) isheated through its melting point. The recordedmelting point of this standard is compared to theknown melting point, and the difference iscalculated for temperature calibration.

In addition, you can use up to four other stan-dards to calibrate temperature. If you use onepair of known and observed points, the entirecurve is offset, or shifted, to the actual meltingpoint. If you use multiple standards, the tem-perature is corrected by a cubic spline fit. Themultiple-point temperature calibration is moreaccurate than the one-point calibration.

For all probe types, except the film/fiber acces-sory, small flattened pieces of standard metalsare placed on the stage. To protect the stagefrom amalgamation with the metal, it is recom-mended that aluminum or platinum be placedbetween the stage and the metal standard. Theend of the probe can also be wrapped with foilfor added protection.

For the film/fiber probe, metal wires can becrimped into the aluminum balls and used forcalibration.

When to Calibrate:

The sample thermocouple should be calibratedin the following situations:

• When the TMA is first installed

Running Experiments


� When the sample thermocouple is changed

� When the TMA is serviced or repaired

� Periodically (approximately once a month)

� If you are changing the temperature range ofinterest

� If the run data obtained seems to beinaccurate.

Regardless of the size or shape of the sample that youare running on the TMA, position the tip of the thermo-couple so that it bends at a 90° angle and lies flatagainst the platform. It should be close to, but nottouching the sample.

NOTE:


Cell ConstantCell constant calibration is based on a run inwhich a known sample (standard) is heatedthrough its transition temperature and data isgathered for analysis. The cell constant iscalculated by dividing the actual coefficient ofexpansion of the standard by the measuredcoefficient of expansion. The cell constant isthen entered in the instrument control softwarefor calibration of the instrument.

Using the default cell constant value of 1.000 isusually adequate; however, for greatest accu-racy, calibration should be performed.

It is recommended that you follow the proce-dures of ASTM Standard Test Method E831 toperform the cell constant calibration. Thismethod is summarized as follows.

1. Place your reference material (normallyaluminum) on the stage (sample platform).

2. Using a 0.01 to 0.05 N force, with thestandard expansion probe, measure thesample length.

3. Heat the sample from 20°C below thetemperature range of interest to 20°C abovethe temperature range at 5°C/min heatingrate.

4. Use a data analysis program to analyze theexpansion of the aluminum over the tem-perature range of interest.

5. Calculate the cell constant using the follow-ing equation:

Expected (literature) expansionObserved expansion

Kcell

=

Calibrating the TMA

Running Experiments


Running aTMA Experiment

Experimental Procedure

All of your TMA experiments will have thefollowing general outline.

• Zeroing the probe

• Selecting and preparing a sample. Thisinvolves preparing a sample of theappropriate size, and placing the sample inthe sample stage.

• Entering experimental information throughthe TA controller.

• Creating and selecting the thermal methodon the controller.

• Setting up any external accessories.

• Adding coolant to the furnace reservoir (forsubambient operation).

• Starting the experiment.


Running a TMA Experiment

Selecting a Probe

The type of probe that you use is dependentupon the kind of testing information desired.The table below lists the probes available, theirspecifications, and the type of testing yielded.

Table 3.1TMA 2940 Probes

Probe Type Contact Pressure TypesDiameter Exerted by of Testsmm (in.) 0.01 N Load Yielded

Penetration 0.89 (0.035) 16 kPa Softening pointMelting point

Expansion 2.54 (0.100) 1.9 kPa Expansion coefficientCompression modulusTensile modulusGlass transition

MacroExpansion 6.07 (0.239) 0.34 kPa Expansion

coefficientCompression modulusTensile modulusGlass transition

Refer to Chapter 4, “Using Your Options,” fordetails regarding the optional probes.

NOTE:

Running Experiments


When choosing a probe to use for an experi-ment, follow these steps:

1. Select the appropriate probe for the analysisdesired.

2. Check the instrument to see which probe iscurrently installed. If you change the probecurrently on the TMA, turn to:

� Chapter 2 to install the expansion andpenetration probes.

� Chapter 4 to install any optional probes.

3. Select the mode that is appropriate for thetype of probe installed. Refer the the onlinedocumentation for information.

4. Calibrate a newly installed probe as de-scribed on page 3-5, or �zero� an alreadyinstalled probe as described in the nextsection.

Zeroing the AutoMeasure System

This procedure is used to initialize the auto-length measure system. It should be performedperiodically to ensure accurate sample lengthmeasurements. To zero the TMA auto measuresystem, simply press the ZERO LENGTH keyon the keypad.


Sample Preparationand Loading

Sample Preparation

Samples used for penetration and expansionstudies should have the following characteristics:

• They should be as flat as possible, withparallel ends, to ensure stable placement onthe stage.

• Samples should be long enough (5 to 10 mmfor most materials) for adequate resolution,keeping in mind that large samples mayexperience temperature gradients duringhigh heating rates.

• Thermoplastic samples can be heated andformed into suitable specimens and thencooled; however, this process may changeimportant thermal history.

Sample Loading

After your sample has been prepared, followthese steps to load it on the TMA 2940:


2. Remove any previously run samples fromthe stage and ensure that no residue remains.

3. Press ZERO LENGTH on the keypad toprovide a zero reference point.

4. Open (raise) the probe. (Press PROBE ▲key twice).


Running Experiments


5. Place the sample on the stage under theprobe tip (see Figure 3.1).

It is recommended that you place a quartz waferor a piece of thin aluminum foil between the stageand any thermoplastic samples to prevent damageto the stage.

Figure 3.1Loading a Sample

6. Adjust the sample thermocouple, if needed,as directed on the next page.

7. Program the force on the controller ,or addweight to the weight tray, if desired. Be sureto enter any static weight added to theweight tray on the instrument control pro-gram; see the online documentation fordetails.

NOTE:


Low force levels may accentuate vibration-induced signalnoise.

8. Measure the sample length by pressing theMEASURE LENGTH key.

9. Move the furnace back into position andclose it.

ThermocouplePositioning

Follow these guidelines as you position thethermocouple on the stage with the sample:

Regardless of the size or shape of the samplethat you are running on theTMA, position the tip of thethermocouple so that itbends at a 90° angle and liesflat against the platform. Itshould be close to, but not touchingthe sample (as shown here):

Measuring theSample Length

Before you begin the experiment, it is importantto take an initial measurement of the sample. Todo this, simply press the MEASURE LENGTHkey on the instrument keypad. This automati-cally measures and stores the sample length onthe TA controller.

NOTE:


Running Experiments


Setting Up anExperiment

Once you have prepared the sample, the nextstep in your experiment is to enter the neededinformation in the TA controller. All of thecontroller functions described in this section areaccessed through the Instrument Control func-tions. Refer to the online documentation to learnhow to perform the following steps.

1. Select the Instrument.

2. Select the Instrument Mode.

3. Enter Sample Information.

4. Enter Instrument Information.

5. Create and Select Thermal Methods.

The first time you use your TMA 2940 you willneed to create at least one thermal method tocontrol experiments. Each method is made ofseveral segments, or individual instructions (e.g.,Equilibrate, Ramp), that control the state of theinstrument.


Setting UpAccessories

If your experiment requires external accessories,ensure that they are turned on, and make anynecessary adjustments before you start yourexperiment. Make sure that the system canachieve the conditions of all segments in themethod.

This section describes how to use the followingaccessories with the TMA 2940:

� Air cool option� Purge gas� TA Instruments Gas Switching Accessory

Using Air Cool

Before you start an experiment that uses the aircool option or the �Return to temperature range�at method-end option, ensure that the supplyvalve from the air source is open and that thepressure is regulated to between 25 and 120 psig.


Running Experiments


Using a Purge Gas

You can control the sample atmosphere duringTMA experiments by connecting a purge gas tothe system. You can purge the system usinginert gases or reactive gases such as air andoxygen. The following gases can be used:

� Helium (recommended)� Nitrogen� Oxygen� Dry, filtered air (to keep moisture, dirt, oil,

and debris out of the system).

If an inert atmosphere is needed, nitrogen gasshoule be used. Close the furnace and purge thesystem with nitrogen for ten minutes. Thenswitch to helium gas for the experiment, ifdesired. To ensure an inert environment foryour sample, a purge rate of 100 mL/min issuggested. Enter the purge gas and flow rateinformation using Instrument Control function,see the online documentation for details. Thesample purge connection is located on the rightside of the back of the TMA. See Chapter 2 forinstallation details.

Suggestions

The following guidelines are suggested whenpurging the system:

� Pass the purge gas through a dryerwhenever you are working at subambienttemperatures in order to remove anymoisture in the gas itself.


� Because of its conductivity, helium is thepurge gas recommended when performingTMA measurements at temperatures belowambient. Helium reduces the time requiredto cool the sample, provides a more stablesample environment, and reduces colddrafts on the system mechanism.

� Use the following helium purge rates forsubambient operation:

� 100 mL/min at -100oC and above� 200 mL/min at -150oC and above.

� If a denser purge gas than helium is used forsubambient experiments, it is recommendedthat the silicon washer found in theaccessory kit be attached to the probe.Raise the probe to the fully open position,then place the washer so it is just below theopening in the stage. This will minimizecold drafts into the lower balance enclosure.

� Let the purge gas flow for 3 to 5 minutesbefore adding coolant or starting the run;this allows a thorough exchange of sampleatmosphere.


Running Experiments


Starting anExperiment

You can begin the experiment using either theSTART key on the TMA keypad or Start on thecontroller.

Stopping anExperiment

If for some reason you need to discontinue theexperiment, you can stop it at any point bypressing either the STOP key on the TMAkeypad or Stop on the controller. Anotherfunction that stops the experiment is Reject(SCROLL-STOP on the keypad) or Reject onthe controller. However, the Reject functiondiscards all of the data from the experiment; theStop function saves any data collected up to thepoint at which the experiment was stopped.

The REJECT function discards all experimentdata.

Removing Samples

After the experiment has completed, allow thesample to cool down so that you can touch it;then the sample can be removed as follows:

1. Raise the furnace and move it off to the side.

2. Open the probe.

3. Use tweezers to remove the sample from thestage. If the sample is stuck to the stage orprobe, do not attempt to mechanicallyremove the material (e.g., by scraping orpulling) as this may cause damage.

t CAUTION:


� To clean off polymeric material,carefully apply heat to the stage andprobe area, removing the sample as itsoftens. Take care not to overheatmineral- or glass-filled polymers as thiswill cause the filler to stick to the stageor probe.

� To remove metallic materials (e.g.,indium), immerse the probe and stage inan acid solution.

Use extreme caution when working withacid solutions.

Heat is not recommended with metallicmaterials, as heat causes the metal todiffuse into the quartz and will changethe properties of the stage and probe.


t CAUTION:

Running Experiments


SubambientExperiments

The TMA can be used to run experiments oncooled samples with a cooling source such asliquid nitrogen. In order to perform subambientexperiments the furnace must work against thecoolant in the reservoir. Ideally, you should usethe least amount of coolant necessary to keep thefurnace drawing power over the entire sub-ambient range.

If the “Return to temperature range” method-endcondition is activated in the instrument control program,press the STOP key to deactivate it before trying to coolthe TMA.

Performing aCooling Experiment

To run a subambient experiment perform thesame operations as described in "Running aTMA Experiment" on pages 3-10 to 3-20. Oncethe sample is loaded and the furnace is lowered,conduct the following operations:

1. Turn on the purge gas at 100 mL/min andallow it to flow for 3 to 5 minutes to ensurea moisture-free environment.

2. Pour coolant carefully into the top of thefurnace, refilling it as needed in order tocool the sample below the desired tempera-ture.

NOTE:


If using liquid nitrogen as a coolant, be sure to follow allof the safety precautions listed in the front of thismanual for handling liquid nitrogen.

3. Start the run.

Adjusting the coolant during the course of the runmay cause nonlinear heating rates, which will bereflected in noisy or discontinuous curves.

Techniquesfor ImprovedSubambientOperation

In order to perform subambient experiments, thefurnace must work against the coolant in thefurnace reservoir. Ideally, you should use theleast amount of coolant necessary to keep thefurnace drawing power over the entire subambi-ent range.

To improve the accuracy of your coolingexperiments, the following guidelines have beensuggested:

� Pass the purge gas through a dryer and useimpermeable tubing whenever you areworking at subambient temperatures inorder to remove any moisture in the gasitself.

Between -20 and +20oC, false transitions mayoccur if moisture is present in the sampleenvironment.

t CAUTION:

NOTE:

Subambient Experiments

Running Experiments


• Because of its conductivity, helium is thepurge gas recommended when performingTMA measurements at temperatures belowambient. Helium reduces the time requiredto cool the sample, provides a more stablesample environment, and reduces colddrafts on the system mechanism.

• Use the following helium purge rates forsubambient operation:

— 100 mL/min at -100oC and above— 200 mL/min at -150oC and above.

• If a denser purge gas than helium is used forsubambient experiments, it is recommendedthat the silicon washer found in theaccessory kit be attached to the probe.Raise the probe to the fully open position,then place the washer so it is just below theopening in the stage. This will minimizecold drafts into the lower balance enclosure.

• If slow heating rates or isothermal holds aredesired at subambient temperatures, it isrecommended that the aluminum massfound in the accessory kit be inserted intothe furnace reservoir. This adds a morestable cooling mass for the furnace to workagainst.

Do not program furnace temperaturesgreater than 600oC when using the aluminumthermal mass.

ttttt CAUTION:


CHAPTER 4: Using Your Options

Overview ..................................................... 4-3

Film/Fiber Accessory .................................. 4-4

Description ........................................... 4-4

Operating Procedures ........................... 4-5

Accessory Installation .......................... 4-5

Removing the Existing Probe ........ 4-6Removing the Stage ....................... 4-6Changing the Instrument Mode ..... 4-7Installing the Film/Fiber Probe ..... 4-7Installing the Film/Fiber Stage ...... 4-8Calculating the Offset .................... 4-9

Calibration .......................................... 4-11


Using the Aluminum Balls .......... 4-12Using the StainlessSteel Clamps ................................ 4-14

Flexure Accessory .................................... 4-17

Description ......................................... 4-17


Calibration .......................................... 4-18


Using Your Options


Dilatometer Accessory.............................. 4-21

Description ......................................... 4-21

Operating Procedures ......................... 4-23

Considerations ............................. 4-23


Calibration .......................................... 4-24

Baseline Calibration .................... 4-24Displacement Calibration ............ 4-25


Parallel Plate Rheometer Accessory ......... 4-29

Description ......................................... 4-29


Calibration .......................................... 4-30


Sample Encapsulating Press ........ 4-31Preparing Moldable Powders ...... 4-35Preparing Resinous Materials ...... 4-38Preparing Sheet Materials. ........... 4-40

Sample Loading ................................. 4-41

Cleanup ........................................ 4-42

Calculations ........................................ 4-43

Hemispherical Probe ................................. 4-47


Overview

OverviewThis chapter explains the optional accessoriesthat you can purchase to use on your TMA 2940,including the following information for eachoption:

� Description� Operating procedures� Accessory installation instructions� Calibration� Sample preparation.

Using Your Options


Film/Fiber Accessory

Description

The TMA film/fiber accessory can be used tomeasure the physical properties of fibers or filmsas a function of force, temperature, or time.

Sample tensile stress is calculated using thefollowing equation:

ST = F / A

where:

ST = stress attemperature T(Pascals)

F = force (Newtons)

A = cross-sectional area(meters2).

The film/fiber accessory kit contains:

� Film/fiber probe� Film/fiber stage� Vial of cleaved aluminum balls� Stainless steel clamps� Clamp block� Screwdriver� Auto Measure gauge.



OperatingProcedures

Film or fiber samples, held in tension duringoperation, are generally longer than expansionor penetration samples, therefore, the smalltemperature gradient normally present in thefurnace is more significant. A faster heating rateserves to accent this gradient. For the bestreproducibility, when creating a method, use aRamp segment of 5oC/min or less for yourheating rate. (See the Thermal Solutions/Advantage User Reference Guide for details.)

When comparing run data, make sure that allcomparison scans are made with the thermo-couple in the same position and at the sameheating rate.

AccessoryInstallation

Because the configuration of the film/fiberaccessory is different from the other types ofprobes, you will need to perform the followinggeneral steps to install the special film/fiberprobe and stage:

� Remove the existing probe� Remove the stage� Change the instrument mode� Install the film/fiber probe� Install the film/fiber stage� Calibrate the probe� Calibrate temperature and cell constant.

NOTE:

Using Your Options


Removing theExisting Probe


2. Grasp the top of the probe with one handand locate the probe-locking lever (behindthe door that covers the weight tray) withyour other hand.

3. Unscrew the locking lever by turning itcounterclockwise approximately one turn.

4. Lift the probe gently and twist slightly to aidits removal from the stage opening.

Removing the Stage

1. Remove the stage shield from the base of thestage by lifting it straight up. (This is afriction fit.)

2. Take off the spring clip that holds thesample thermocouple in place.

3. Move the thermocouple off to the side of thestage.

4. Turn the stage nut counterclockwise toremove it.

5. Twist the stage retainer ring (with key slots)counterclockwise, pull it up off the threeposts, and slide it up off the stage.

6. Take the wave washer up off the stageflange and remove it.

7. Remove the stage from the stage opening.


Changing theInstrument Mode

To learn how to change the instrument mode,refer to the Thermal Solutions/Advantage UserReference Guide for instructions.

The instrument must be placed into the film/fibermode before installing the film/fiber accessory inorder to prevent damage to the instrument or tothe accessory.

Installing the Film/Fiber Probe

The special configuration of the film/fiber acces-sory requires the installation of the probe beforethe stage.

1. Insert the core end of the probe carefullyinto the opening in the top plate.

2. Open the weight tray door and locate theprobe-locking lever.

3. Loosen the probe-locking lever and hold itin the up position. Continue lowering theprobe until you can feel it exerting down-ward pressure on the locking lever.

4. Align the slot in the top of the probe front toback and tighten the probe-locking lever byturning it clockwise.

5. Close the weight tray door.


t CAUTION:

NOTE:

Using Your Options


Installing the Film/Fiber Stage

1. Lower the film/fiber stage down carefullyover the probe onto the base.

2. Place the wave washer over the top of thestage and probe assembly and lower it ontothe flange.

3. Slide the stage retainer ring carefully overthe top of the stage and probe assembly sothat it rests on top of the wave washer. Pushdown and turn clockwise to tighten theretainer ring.

4. Carefully align the stage slot with the slot inthe top of the probe and position the stageopening to the front. (See Figure 4.1.)

Figure 4.1Film/Fiber Stageand Probe Assembly

5. Replace the large stage nut and turn itclockwise to insert it.


6. Attach the thermocouple to the stage asfollows:

a. Position the tip of the thermocoupleapproximately one half the length of thesamples you will be measuring. The tipshould be angled toward the samplelocation.

After installing the thermocouple, tip placementmay interfere with the zero length operation.Temporarily move the thermocouple when per-forming this operation.

b. Hold the thermocouple against the stageassembly and put on the spring clip tohold the thermocouple in place.

7. Replace the stage shield on the base of thestage.

8. Move the furnace back into position andlower it. See Figures 4.4 and 4.7 for thecorrect probe setup with fiber and filmsamples.

Calculatingthe Offset

When you use the film/fiber accessory, analysismust compensate for the thickness of the stageplatform and the upper portion of the probe.Perform the �Auto zero offset� procedure tocompensate for the thickness. (See the ThermalSolutions/Advantage User Reference Guidefor further instructions on performing thisoperation.)


NOTE:

Using Your Options


The Auto Measure Offset will not need to bechanged unless you:

� Reset the instrument parameters.

� Use a new film/fiber probe and stageassembly.

1. Record the value listed as Auto MeasureOffset from the TA controller.

2. Use calipers to measure the gap in the AutoMeasure Offset Gauge and record this valueas the Actual Size.

3. Open the probe and insert the gauge asshown in Figure 4.2.

Figure 4.2Inserting theAuto Measure Gauge


4. Press the Measure Length key on thekeypad. Record this value as the DisplayedSize.

5. Calculate the new offset using the followingequation:

Offset new = (Actual Size - Displayed Size) +Offset current

6. Enter the new Auto Measure Offset usingthe Thermal Solutions/Advantage Instru-ment Control functions.

7. Remove the Auto Measure Gauge andproceed with your experiment.

CalibrationYou should perform probe, temperature, and cellconstant calibration for the film/fiber accessoryas you would normally calibrate any of thestandard probes. Metal wires crimped in thealuminum balls should be used for temperaturecalibration. High quality aluminum foilclamped in the steel clamps should be used forcell constant calibration. See the ThermalSolutions/Advantage User Reference Guidefor details.


Using Your Options


SamplePreparation

The method used to prepare and load yoursample varies according to the sample type.There are two methods available for the film/fiber accessory: aluminum balls or stainlesssteel clamps.

Using theAluminum Balls

The aluminum balls are generally used withfiber samples as follows:

1. Measure and cut the fiber sample slightlylonger than desired length, typically 12 to 25mm (0.5 to 1.0 inch).

2. Place two cleaved aluminum balls 12 to 25mm (0.5 to 1.0 inch) apart.

3. Lay the fiber across the balls and press thefiber into the cleavage of each ball (seeFigure 4.3).

Figure 4.3Fiber SamplePreparation

Sample Length12 to 25 mm(0.5 to 1.0 inch)


4. Crimp the two balls closed. The balls shouldnot shift or slip when tested by hand.

5. Cut off any excess fiber extending beyondthe aluminum balls.

6. Place one ball over the slot in the stage withthe fiber hanging down through the slot andallow the other ball to hang freely.

7. Position the second ball below the slot in thefilm/fiber probe so that the fiber is sus-pended between the two balls as shown inFigure 4.4.

8. Measure the sample length.

9. Position the thermocouple close to, but nottouching the sample.

Figure 4.4Probe SetupUsing Fiber Samples


Using Your Options


Using the StainlessSteel Clamps

The stainless steel clamps may be used witheither film or fiber samples as follows:

1. Measure and cut the sample to the desiredlength, typically 12 to 25 mm (0.5 to 1.0inch). (Films should have a uniform width.)

2. Separate the jaws of one clamp. Positionthe clamp so that the clamp relief notchopening is at the top of the sample, thenslide one end of the sample into the clampand tighten the screws. (See Figure 4.5.)

Figure 4.5Stainless SteelClamps and Sample


3. Lay the clamp and sample into the sampleblock so that the clamp fits into the notch onone end.

4. Lift up the free end of the film and slide theother clamp onto the end, positioning theclamp relief notch opening at the bottom ofthe sample (see Figure 4.5).

5. Move the clamp into the desired notchposition (for either a 9, 13, or 25-mmsample).

6. Tighten the screws so that the sample is flatin the block and is positioned perpendicularto the clamps (see Figure 4.6).

Figure 4.6Film SamplePreparation

7. Remove the clamps and sample from theblock and trim off the excess material.

8. Place one clamp on edge over the slot in thefilm/fiber stage so that the film hangs downinto the slot.


Using Your Options


9. Position the second clamp below the slot inthe film/fiber probe so that the film issuspended between the two clamps asshown in Figure 4.7.

10. Measure the sample length.

11. Position the thermocouple close to, but nottouching the sample.

Figure 4.7Probe SetupUsing Film Samples


Flexure Accessory

Flexure AccessoryDescription

The Flexure Accessory can be used on the TMA2940 for three-point bending studies to measurethe flexibility and strength of a variety ofmaterials including: composites, plastics, PCboards, etc. It employs a knife-edged probe anda sample platform with two knife edges spaced5.08 mm (0.2 inches) apart. This accessorypermits the determination of deflection tempera-ture under load.

Required loading is calculated using the follow-ing equation:

2 Sbd2

P =3 L

Where:

P = calculated load (N)

S = maximum fiber stress (Pa)(1 psi = 6.895 x 103 Pa)

b = sample width (m)

d = sample depth (m)

L = width of span between theknife edge supports of theflexure platform(5.08 x 10-3 m).

The flexure accessory kit contains:

� Flexure probe assembly� Flexure sample platform.

Using Your Options


Accessory Installation

The flexure accessory uses a special flexureprobe and sample platform, and the standardstage.

1. Remove the existing probe as instructed onpage 2-19.

2. Install the standard stage, if it is not alreadyin place. (For instructions to install thestage, refer to page 2-14).

3. Install the flexure probe in the same manneras the standard expansion and penetrationprobes as instructed on page 2-18.

4. Change the instrument mode, if necessary.

CalibrationThe flexure probe should be calibrated as youwould normally calibrate any of the standardprobes. See the Thermal Solutions/AdvantageUser Reference Guide for details.


SamplePreparation

Samples used with the flexure accessory shouldhave the following specifications:

� No wider than the flexure platform� Uniform width and thickness� Thick enough to be rigid when placed on

flexure platform� 7 to 10 mm long.

To load your flexure samples on the TMA 2940,follow these steps:



3. Open the probe.

4. Place the flexure platform on top of thestage

5. Place the sample on the flexure platform sothat it is centered across the points.

6. Position the sample and platform on thestage under the flexure probe tip so that theprobe knife edge is parallel to the platformpoints and is centered between them (seeFigure 4.8).


Flexure Accessory

Using Your Options


Figure 4.8Probe Setup UsingFlexure Samples

8. Adjust the thermocouple position so that itis in close proximity to the sample.

9. Move the furnace into position and lower it.


Dilatometer Accessory

DescriptionThe dilatometer accessory kit can be used todetermine the volume coefficient of expansion.The cubic expansion of a sample is calculatedusing the following equation:

K � (S � B)

b =V

where:b = coefficient of expansion

m3

m3 oC

K = vial constant (cm3/µm)

S = slope (µm/oC)

V = sample volume (cm3). Thisvolume may be obtained bydividing the sample mass ingrams by its density in g/cm3 atroom temperature.

B = slope of baseline (µm/oC).


( )

Using Your Options


To calculate the vial constant from a scan usethe following equation:

bref

� VK =

(S � B)

where:

K = vial constant (cm3/µm)

S = slope (µm/oC)

bref

= cubic expansion coefficient ofstandard material m3

m3 oC

bref

= 3 aref

Where aref

is the coefficient oflinear expansion of standardmaterial, (m/m � oC), measuredover the same temperature range.

V = sample volume (cm3). This volumemay be obtained by dividing thesample mass in grams by its densityin g/cm3 at room temperature.

B = slope of baseline (µm/oC).

The dilatometer accessory kit contains:

� Dilatometer probe assembly� Dilatometer sample vial� Filling medium� Aluminum calibration standards.

( )


OperatingProcedures

Considerations

The vial, filling medium, and sample assemblytogether make up a large thermal mass. Becauseof this large thermal mass, it is recommendedthat a slow heating rate be used to allow thesample to maintain the heating rate as sensed bythe sample thermocouple. When creating amethod, use a Ramp segment of 3 to 5oC/min orless for your heating rate.

If you compare data runs, make sure that allcomparison scans are made with the vial filled tothe same level with filling medium, with thethermocouple in the same position, and heated atthe same rate.


The dilatometer accessory uses the dilatometerprobe, dilatometer sample vial and the standardstage.



3. Insert the core end of the dilatometer probecarefully into the opening in the stage.


NOTE:

Using Your Options


4. Hold the probe-locking lever in the upposition and continue lowering the probeinto the stage until you can feel it seat in thelocking mechanism.

5. Tighten the probe-locking lever by turning itclockwise.

6. Position the sample thermocouple on thestage so that the tip is 13 mm (0.5 inch)above the stage.

7. Change the instrument mode, if needed.

CalibrationIn addition to the normal probe calibration, thedilatometer accessory should be calibrated forbaseline and displacement using the proceduresdescribed as follows.

BaselineCalibration

The dilatometer filling medium must be kept dry.Store it in a desiccator when it is not being used.If the sample has become contaminated throughlong exposure to humidity, dry it in a vacuum ovenat 200oC for one hour.

Run a thermal scan, under the same load thatwill be used when analyzing your samples(typically 0.01 N or less). Use a vial three-quarters full with filling medium only (nosample). Make sure the filling medium is wellpacked.

Marking the vial at the fill level and filling future sampleruns to this level will insure that the baseline effect dueto the fill medium are minimized from run to run.

NOTE:

NOTE:


DisplacementCalibration

Calibrate the dilatometer for cubic displacementusing the following procedure:

1. Take three aluminum balls from the dilatom-eter accessory kit to use as a calibrationsample.

2. Weigh the three aluminum balls and preparethe sample and vial as instructed on thefollowing pages. Make sure that the alumi-num balls do not touch the walls of the vial,and that they do not touch ech other.

3. Obtain a thermal scan under the sameconditions of the baseline scan (e.g. sameload and heating rate).

4. Calculate the vial constant from the scan byusing the equation found on page 4-22.


Using Your Options


Sample Preparation

The following method is used to prepare andload the dilatometer sample:

The dilatometer filling medium must be kept dry.Store it in a desiccator when it is not being used.If the sample has become contaminated throughlong exposure to humidity, dry it in a vacuum ovenat 200oC for one hour.

1. Fill the dilatometer vial one-third full withthe filling medium found in the accessorykit.

2. Use a tamping rod to lightly pack the fillingmedium.

3. Select a sample that is small enough toeasily fit inside the dilatometer vial withouttouching the walls.

4. Place the sample on the filling medium inthe center of the vial. Make sure that thesample does not touch the vial walls.

5. Add more filling medium to the vial until itis approximately three-quarters full, thentamp down the filling medium hard with atamping rod. The level will be compacted.Continue adding filling medium and tamp ithard until the vial remains three-quartersfull. Mark this position on the vial.

6. Check the filled and packed dilatometer vialfrom all angles to make sure that the sampledoes not show (see Figure 4.9).

NOTE:


Figure 4.9Dilatometer SamplePreparation



9. Open the probe.

10. Place the vial on the stage.

11. Close the probe until the probe tip is posi-tioned above the filling medium.

12. Tap lightly on the upper probe assembly, theprobe should oscillate freely within the vial.

13. Close the probe until it just rests on top ofthe filling medium. Gently tap the probe toseat it (see Figure 4.10).


Using Your Options


Figure 4.10Probe Setup UsingDilatometer Samples


15. Adjust the thermocouple position so that itis in close proximity to the vial.

To avoid false thermocouple readings, make surethat the thermocouple tip does not touch thesample vial.


17. Program the force (typically 0.01 N or less)using Thermal Solutions/Advantage.

18. Check that the sample size is equal to zerobefore beginning your experiment.

NOTE:


Parallel PlateRheometer Accessory

DescriptionThe parallel plate rheometer accessory can beused to obtain viscosity-temperature or vis-cosity-time data on substances at low shearrates, over the range of 10 to 107 Pa-sec (1 to 106

Poise).

The parallel plate rheometer accessory kitcontains:

• Sample-forming die set• Parallel plates• Alignment cage.


The parallel plate rheometer accessory uses themacro expansion probe, rheometer sampleholder assembly, and the standard stage.



3. Install the macro expansion probe in thesame manner as the standard expansionand penetration probes as instructed onpage 2-18.

4. Change the instrument mode, if needed.

Parallel Plate Rheometer Accessory

Using Your Options


5. Position the sample thermocouple on thestage so that the tip is 13.0 mm (0.5 inch)above the stage.

To avoid false thermocouple readings, make surethat the thermocouple tip does not touch thealignment cages or plates. Exposed portions ofthe two thermocouple leads must not touch eachother.

CalibrationThe parallel plate rheometer accessory should becalibrated as you would normally calibrate anyof the standard probes. See the ThermalSolutions/Advantage User Reference Guidefor details.

NOTE:


SamplePreparation

The parallel plate rheometer employs cylindricalsamples that are 9.53 mm (0.375 inch) indiameter and 0.25 to 1.00 mm (0.01 to 0.04inch) in thickness. Three types of samples canbe used with the rheometer accessory:

• Moldable powders• Resinous materials• Sheet materials.

In order to obtain a sample having the correctcylindrical dimensions, the material must beprepared according to the directions in thissection. Moldable powders and resinousmaterials employ the use of the Sample Encap-sulating Press (PN 900680.902) and a special setof dies, the pellet press die set.

To prepare samples follow the instructionsfound in these sections:

• Sample Encapsulating Press__see below• Preparing Moldable Powders__page 4-35• Preparing Resinous Materials__page 4-38• Preparing Sheet Materials__page 4-40.

SampleEncapsulatingPress

This accessory (see Figure 4.11) is used to formsamples into a compact, cylindrical disc. Inorder to use it for parallel plate rheometersamples, you must first remove the Encapsulat-ing Press hermetic sealing or non-hermeticcrimping die assembly. After these dies havebeen removed, the pellet press die set can beinstalled.


Using Your Options


Figure 4.11SampleEncapsulating Press

Removing the Existing Die Assembly

The plunger in the upper hermetic die assem-bly is spring-----loaded and should be removedwith care.

1. Lower the Encapsulating Press handle.Then rotate the die-holder assembly andupper crimping die (if installed), so that thesocket head setscrews are accessible throughthe hole in the Encapsulating Press housing.

!WARNING


The upper crimping die is installed over, and lockedto, the upper hermetic die.

2. Loosen only the setscrew in the uppercrimping die (if installed), raise the presshandle, and remove the die assembly(including the crimping plunger).

3. Lower the press handle and loosen thethumbnut located on the side of the presscolumn.

4. Lay the Encapsulating Press on its side andscrew in the lower die-holder/adjustmentscrew (located on the bottom of the press),until the lower die holder (either hermetic orcrimping) just meets the upper hermetic die.

5. Loosen the setscrew in the EncapsulatingPress upper die-holder assembly to unlockthe upper hermetic die.

The upper hermetic die is now held in position byeither the lower hermetic or crimping die.

6. Unscrew and remove the lower die-holderadjustment screw. This allows removal ofthe lower hermetic or crimping die andupper hermetic die assembly (includeshermetic plunger and spring).

As the lower die-holder adjustment screw is beingremoved, spring tension on the hermetic dieplunger is relieved.

7. Set the press upright; it is now ready for therheometer pellet press die installation.


NOTE:

NOTE:

NOTE:

Using Your Options


Installing the Pellet Press Die Set

1. Remove the hermetic sealing or non-hermetic crimping die assembly as describedin the preceding procedure.

2. Lower the Encapsulating Press handle andinsert the pellet press piston into the upperdie-holder assembly as far as it will go.Secure the piston in place by tightening thesetscrew in the upper die-holder assembly.

3. Lay the Encapsulating Press on its side andscrew in the pellet press base screw until itis nearly flush with the bottom of the press.

4. Place the pellet press cylinder head, cavityside down, on top of the pellet press basescrew.

5. Lower the pellet press piston by bringing thehandle forward until it is parallel with thepress base. Adjust the pellet press basescrew until the flat surface of the cylinderhead meets the piston. Tighten thethumbnut, on the side of the press column,finger-tight.

6. Set the press upright. Install the pellet presscylinder into position on the cylinder headwith the recessed portion of the cylinderfitting snugly onto the cylinder head (seeFigure 4.12).


Figure 4.12Encapsulating Presswith Pellet Press Die Set

Preparing Moldable Powders

To prepare moldable powder samples for usewith the parallel plate rheometer accessory,follow these instructions:

1. Install the pellet press die set in the Encap-sulating Press.

2. Pour sufficient sample material (~30 to 50mg) into the pellet press cylinder to producea disc 0.25 to 1.00 mm in thickness.

3. Lower the pellet press piston by bringing theEncapsulating Press handle forward. Firmlypress the handle down to form the sampledisc.


Using Your Options


4. Raise the Encapsulating Press handle andremove both the pellet press cylinder andcylinder head from the press.

5. Remove the cylinder head from the cylinderand reverse its position so that the cavityside of the cylinder head now faces thecylinder. Note the position shown in Figure4.13.

Figure 4.13Cylinder HeadPositions

6. Replace the cylinder head and cylinder inthe Encapsulating Press. Lower the pistonwith the press handle. This will cause thesample disc to drop into the cylinder headcavity. Lift the piston, remove the cylinder,and collect the finished sample disc.

7. Measure the sample thickness, using cali-pers, to within + 0.02 mm.

8. Place the sample between two parallel platesin the alignment cage as shown in Figure4.14.


Figure 4.14Parallel PlateSample Assembly

9. Load your sample according to the direc-tions on page 4-41.


Using Your Options


Preparing Resinous Materials

To prepare resinous materials for use with theparallel plate rheometer accessory, you will needthe following parts to use as a molding form:

• Pellet press cylinder• Cylinder head• Piston.

1. Assemble the pellet press cylinder andcylinder head in the sample-forming posi-tion for use as a mold as shown (see Figure4.15).

Figure 4.15Sample-FormingPosition

2. Heat up a hot plate to about 20oC above themelting point of the sample material.

This procedure involves heating up the sampleand mold assembly. Handle with tongs toprevent burns.

3. Place the mold assembly on the hot plateand allow it to come to temperature.

!WARNING


4. Put enough sample material into the pelletpress to yield a 0.25 to 1.00 mm thick disc(~30 to 50 mg).

5. Place the pellet press piston into the cylinderand add a suitable weight (50 g) on the topof the piston.

6. Note the position of the piston in the cylin-der; as the sample starts to melt, the pistonwill settle.

7. Using tongs, remove the weight when thepiston sinks to its maximum depth.

8. Remove the mold assembly from the hotplate using tongs, and allow it to cool toroom temperature.

9. Disassemble the mold and remove themolded sample disc.


11. Place the sample between two parallel platesin the alignment cage as shown in Figure4.14 on page 4-37.

12. Load your sample according to the direc-tions on page 4-41.


Using Your Options


Preparing Sheet Materials

To prepare sheet materials for use with theparallel plate rheometer accessory, follow theseinstructions:

1. Cut a sample from a sheet of material 0.25to 1.00 mm in thickness using a standard 9.5mm hole punch.


3. Place the sample between two parallel platesin the alignment cage as shown in Figure4.14 on page 4-37.

4. Load your sample according to the direc-tions in the next section.


Sample Loading

To load your parallel plate rheometer sampleson the TMA 2940, follow these steps:


2. Open the probe.


4. Place the sample assembly on the stageunder the probe tip (see Figure 4.16 on thenext page).

5. Adjust the thermocouple position so that itis in close proximity to the sample.

To avoid false thermocouple readings, make surethat the thermocouple tip does not touch thealignment cage, sample, or plates. Exposedportions of the two thermocouple leads must nottouch each other.

6. Press Zero Length on the instrumentkeypad so that the probe rests on the topplate and provides a zero reference point.

7. Enter the Sample Size on the ExperimentalParameters window on the controller.


9. Program the force on the Instrument Param-eters window on the controller or addweight to the weight tray, if desired.


NOTE:

Using Your Options


Figure 4.16Probe SetupUsing Parallel PlateRheometer Samples

Cleanup

The heat used in parallel plate rheometerexperiments often cements the parallel platestogether inside the cage. If you want to reusethe parts, follow these directions:

These procedures involve the use of heat orchemicals; appropriate safety measures shouldbe observed at all times.

Thermoplastic material

1. Heat the plates and cages gently in a burnerflame to separate them.

2. Allow the parts to cool, then scrape themclean with a small spatula.

ttttt CAUTION:


Thermosetting material

Soak the plates and cages in a suitable solvent toseparate and clean them.

or

Heat the parts to red heat in the oxidizingportion of a burner flame. The organic materialshould oxidize completely.

or

Heat the plates in a furnace to approximately1000°C.

Calculations

Correction Calculations for ThermalExpansion of Parallel Plates

1. Calculate the apparent distance between theplates (h*) at a given temperature (or time)by subtracting the decrease in distancebetween the plates (in mm) from the originalsample height.

Equation:

h* = sample thickness – dimension change(mm) (mm)

2. Correct the distance between the plates forthermal expansion.

Each plate is nominally 5.08 mm (0.2 inch)stainless steel. Therefore, the total dimen-sion for both plates is 10.2 mm (0.4 in.).


Using Your Options


The expansion coefficient (α) for stainlesssteel as a function of temperature is shownin Table 4.1 on the next page.

a. Choose the appropriate coefficient ofexpansion (α) value for stainless steel atthe desired temperature.

b. Multiply this a by the total plate thick-ness and the temperature change toobtain the thermal expansion correctionfactor.

c. Subtract the correction factor from theapparent distance between the plates(h*) determined in step 1 to obtain theactual distance between the plates (h).

Where:

h =

h* – [α (µm/m°C) x ∆T(°C) x 10.2 mm

x 10-6 (m/µm)]

3. Calculate 1/h2.

4. Calculate a table of: ∆1/h2

∆t

Where:

h* = apparent distance between plates

h = actual distance between plates

t = time

T = temperature.

versus T



Table 4.1Stainless SteelCoefficient ofExpansion1

T (oC) Coefficient of Expansion (α) (µm/moC)

18 14.8 93 16.0149 16.6204 16.7260 16.9316 17.3371 17.5427 17.6482 17.8538 18.0

1D.E. Furman, J. Metals, 188 <4>, 688 <1950>

Using Your Options


η =

Calculations for Viscosity and WallShear Rate Data

To calculate sample viscosity (η) and wall shearrate (γ), the experimental data is first scaled andcorrected for expansion of the parallel plates (aspreviously shown on page 4-43). Then thiscorrected data is applied to equations developedby Dienes and Klemm (J. Appl. Phys., 17,458,1946) and Cessna and Jabloner (J. Elast. Plast.,6, 103, 1974).

Equation:

4F ∆tx x 106 mm2/m2

3 π r4 ∆(1/h2)

3rh ∆(1/h2)

2 ∆t

where:

F = applied force (N)

r = parallel plate radius (mm)

h = sample height (mm)

t = time (sec)

η = viscosity (Pa-sec)

γ = shear rate (1/sec)

γ = x•

•


Hemispherical ProbeThe hemispherical probe (see Figure 4.16) isused with the standard quartz stage to obtainsoftening point data on substances. It is in-stalled, operated, and calibrated using the sameprocedures as the standard expansion andpenetration probes. Refer to Chapter 2 “Install-ing the TMA 2940” for information on installa-tion.

Figure 4.16Hemispherical Probe

Hemispherical Probe

Using Your Options



CHAPTER 5: Technical Reference

Description of the TMA 2940 ................... 5-3

Uses ofThermomechanical Analysis ................ 5-4

Calculating theCoefficient of Expansion ..................... 5-5

Method Considerations ............................... 5-6

Status Codes ............................................... 5-7


Technical Reference


Description of the TMA 2940

The Thermomechanical Analyzer 2940 iscapable of heating or cooling samples whileapplying a predetermined force on the material.A quartz probe, placed in contact with thesample, is used to determine any linear orvolumetric changes in dimension, at the selectedtemperature and force. Valuable data on melt-ing points, glass transition temperature, expan-sion coefficients, gel time and temperature, resinflow, and delamination temperature can beobtained by the sensitive measuring system ofthe TMA 2940.



Technical Reference

Uses ofThermomechanicalAnalysis

Thermomechanical Analysis is an investiga-tional tool used by various chemical, electronic,pharmaceutical, and manufacturing companiesand labs. It is used for quality control studies,analysis of processing conditions, and perfor-mance characterization of samples. The samplesanalyzed using the TMA vary widely. They caninclude materials such as:

• polymers used in packaging materials• optical and other types of fibers• films of all kinds• cured laminates such as those used in

multilayer printed circuit boards• composites• elastomers• epoxy prepregs• resins, etc.


Calculatingthe Coefficientof Expansion

One of the analyses obtained using the TMA2940 is an expansion profile of a sample. Tocalculate the coefficient of expansion (a experi-mental) from the expansion profile you can usethe Data Analysis program or the followingequation:

∆L x Kα = ∆T x L

Where:

α = measured coefficient ofexpansion (µm/moC)

L = sample length (m)

∆L = change in sample length (µm)

∆T = change in temperature (oC)

K = cell constant.



Technical Reference

MethodConsiderations

Everyone has their own methods to use whenrunning experiments; however, the followingitems may prove useful:

• For measuring thermal expansion, lowforces (0.005 to 0.05 N) are recommended.

• When searching for softening temperatures,studies of penetration temperature vs. forceare helpful to eliminate false values.

• A heating rate of 5oC/min or less is best forpolymeric and elastomeric materials.

• Temperature programs should be startedwell below the temperatures of any knowntransitions, since straight-line extrapolationsare normally used to define transitiontemperatures. As a rule of thumb, start therun 2 to 4 minutes times the heating rate(oC/min) lower than the temperature ofinterest.


Status Codes

Status CodesStatus codes are character strings that arecontinuously displayed at the top left of theTMA instrument display. These codes tell youwhat segment is currently being performed bythe instrument.

Table 5.1Method Status Codes

Code Meaning

Air Cool The air cool solenoid isopened to allow coolingair flow to the furnace.

Balance Force is being appliedto balance the system atthe center of the displace-ment range. This is usedfor force calibration.

Calib The instrument is per-forming LVDT calib-ration or the instrument isin a calibration mode. Nomethod is running.

Cold The instrument heatercannot supply heat fastenough to keep up withthe thermal program.This may be caused by alarge ballistic jump in theprogram, a faulty heater, afaulty control thermo-couple signal.

(table continued)


Technical Reference


Code Meaning

Complete The thermal method hasfinished.

Cooling The heater is cooling, asspecified by a Rampsegment.

Closing The furnace and/or probeassembly is closing.

Equilib The temperature is beingequilibrated to the desiredset point.

Err xxx An error has occurred(xxx will appear as a two-or three-digit code). Thelocal screen will give theError Code number; thecontroller will show thecomplete error message.

Heating The heater temperature isincreasing, as specified bya Ramp segment.

Holding Thermal experimentconditions are holding;the program is suspended.Press START to continuethe run.

(table continued)


Status Codes


Code Meaning

Hot The temperature isbeyond the set point, andthe instrument cannotremove heat fast enoughto follow the thermalprogram. This is usuallycaused by a large ballisticjump to a lower tempera-ture or by running acooling ramp.

Initial The temperature isequilibrating to thedesired set point. Whenthe temperature hasreached equilibrium, thestatus will change to“Ready.”

Iso The thermal program isholding the currenttemperature isothermally.

Jumping The set point is jumpingto a new value.

Measure Measurement of thesample length is inprogress.

No Power There is no power to theheater. Check the heaterswitch and fuse.

Opening The furnace and/or probeassembly is opening.

(table continued)


Technical Reference


Code Meaning

Preheat The furnace is equilibrat-ing at a specified temp-erature. Initially, thefurnace is in the openposition. After thetemperature has equili-brated, the furnace isclosed and held isother-mal for a specified time.

Ramping The force is ramping to aspecified value.

Ready The system has equili-brated at the initialtemperature and is readyto begin the next segment.Press the START key tocontinue the method.

Reject The experiment has beenterminated and the dataerased.

Repeat The method is executing arepeat loop.

Set Up The system is preparing tostart the first segment ofthe method.

Standby The method segments andend-of-method operationsare complete.

(table continued)


Status Codes


Code Meaning

Temp * The temperature calibra-tion is active.

Unstable The Isostrain segment hasbeen initiated, but theinstrument has not orcannot meet the criteriaspecified.

Zeroing The LVDT is beingpositioned to center theprobe in the displacementrange.


Technical Reference


CHAPTER 6: Maintenance andDiagnostics

Overview ..................................................... 6-3

Routine Maintenance .................................. 6-4

Inspection ............................................. 6-4

Cleaning ............................................... 6-5

Cleaning the Keypad ..................... 6-5Cleaning the Probe Assembly ........ 6-5Cleaning the Stage ......................... 6-6Cleaning the Thermocouple........... 6-7

Replacements ....................................... 6-8

Installing a New Thermocouple .... 6-8

Diagnostics ................................................. 6-9

Fuses ..................................................... 6-9

Power Failures .................................... 6-10

TMA 2940 Test Functions ........................ 6-12

The TMA Confidence Test ................ 6-12

Replacement Parts .................................... 6-15

Maintenance and Diagnostics



OverviewThis chapter contains information needed for theefficient operation of the TMA as follows:

• Maintenance procedures needed to keepyour instrument clean and in good workingorder

• Instructions on how to replace certain partswhen needed

• Details on diagnosing fuse problems anddealing with power failures

• Descriptions of the TMA Confidence Tests.

Overview



RoutineMaintenance

In order to keep your ThermomechanicalAnalyzer 2940 in good working condition, themaintenance procedures described here shouldbe performed regularly. Periodic inspection andcleaning are recommended. Any further mainte-nance or repair should be performed by arepresentative of TA Instruments or otherqualified service personnel.

Because there are high voltages in this instru-ment, untrained personnel must not attemptto test or repair any electrical circuits.

Inspection

Examine the instrument for good condition asfollows:

• The furnace area should be clean; anyresidue should be removed before startingthe next experiment.

• The stage, probe assembly, LVDT core, andsample thermocouple should be free of anysample material before the next sample isloaded.

!WARNING


CleaningRegular cleaning of your instrument helps toincrease its longevity and maintain its effi-ciency. Taking a few minutes to clean variousparts of the Thermomechanical Analyzer asdirected, will be well worth the effort.

Cleaning the Keypad

You can clean the instrument keypad as often asdesired. The keypad is covered with a silk-screened Mylar(R)* overlay that is reasonablywater resistant, but not waterproof or resistant tostrong solvents or abrasives.

A household liquid glass cleaner and papertowel are best for cleaning the keypad. Wet thetowel, not the keypad, with the glass cleaner,and then wipe off the keypad and display.

Cleaning theProbe Assembly

After each experiment, check the probe assem-bly. If the probe is dirty, remove it using theprocedures found in Chapters 2 (for standardprobes) and 4 (for optional probes), then clean itas follows:

1. Use contact cleaner or acetone applied witha soft brush or cloth to clean the LVDT coreand the upper probe.

2. Heat the end of the quartz probe with aBunsen burner until the residue evaporatesand the probe is clean. Heat the probe veryslowly if the sample has a large amount ofglass or mineral filler.

* Mylar(R) is a registered trademark of the of theDuPont Company.

Routine Maintenance



Probes may also be cleaned in a nitric acidsolution.

Cleaning the Stage

Dirt or sample residue left on the top of thestage may interfere with the next sample placedon the stage. To maintain proper experimentalconditions, clean the stage as follows:

For small amounts of residue:

1. Use industrial cleaner or acetone on a softcloth to wipe the top of the stage.

For thorough cleaning:


2. Remove the stage shield.

3. Take off the spring clip that holds thesample thermocouple and move the thermo-couple off to the side of the stage.

4. Turn the stage nut counterclockwise toremove it.

5. Twist the stage retainer ring (with key slots)counterclockwise, pull it up off the postsand slide it up off the stage.

6. Take the wave washer up off the stageflange and remove it.

7. Remove the stage from the stage opening.


8. Use industrial cleaner or acetone appliedwith a soft brush or cloth to clean the stagesurface.

9. Heat the stage surface with a Bunsen burneruntil the residue evaporates and the stage isclean. Heat the stage very slowly if thesample has a large amount of mineral orglass filler.

The stage may also be cleaned in a nitricacid solution.

Cleaning the Thermocouple

Sample residue and dirt may interfere with theaccuracy of the thermocouple readings. To cleanthe thermocouple:


2. Remove the stage shield.

3. Remove the spring clip holding the thermo-couple in place.

4. Hold the thermocouple away from the probeassembly and clean gently with a low flameusing a hand-held burner.

Routine Maintenance



Replacements

Occasionally you may need to replace a brokenor worn out part of the TMA. Any replacementsneeded, other than those discussed in thismanual, must be supplied and installed byqualified TA Instruments service personnel. Call(302) 427-4050 for service.

Installing aNew Thermocouple

You may find that the need arises for a newthermocouple (PN 944017.901) as a result ofnormal wear and tear, accidental breakage,contamination of the thermocouple, etc.

Before removing the thermocouple, you willneed to take off the TMA balance enclosure, thestage shield, and the spring clip holding thethermocouple in place. Then carefully thread thethermocouple down through the opening in theplatform and unplug it.

To replace the sample thermocouple, follow thedirections found in Chapter 2, Installation.


Diagnostics

FusesThe TMA contains several internal fuses;however, not one is user serviceable.

Do not attempt to service or replace anyinternal TMA fuses. Call TA InstrumentsService for repair if you suspect an internalfuse problem; a hazardous condition may bepresent in the instrument.

The only fuses that you should service yourselfare the external fuses, located on the TMAcontrol panel. Both of these fuses are housed insafety-approved fuse carriers labeled F1 and F2(see Figure 6.1).

Figure 6.1Fuse Locations

Always unplug the instrument before youexamine or replace the fuses.

Fuse F1 is in the circuit between the mainelectrical input and the rocker switch labeledPOWER. All power for internal operations andinstrument functions, except heater power,passes through this fuse. If this fuse blows, youwill get no response from the system.

Diagnostics

!WARNING

FUSE 1 FUSE 2

!WARNING



Fuse F2 protects the heater coils in the oven.Because F2 does not power the internal logic,you may not know that this fuse is blown untilyou try to heat a sample, since the TMA instru-ment will pass its confidence test with this fuseopen.

Fuse F2 is checked whenever a method is begun.Power supplied by this circuit is switched by acomputer-controlled relay as well as theHEATER switch located on the TMA frontpanel. When both devices are active, the lamp inthe HEATER switch turns on.

Power Failures

A power failure caused by a temporary drop inline voltage can result in one of two responses inthe instrument. If the drop is fairly large and oflong duration (20 milliseconds or more), thesystem will reset and go into its power-upsequence when power resumes. If the drop issmall or of short duration, the system may haltand you may see “Err F02” on the instrumentdisplay.

In the latter case, the system is “hung.” It hasdetected a power failure and shut down. TheTMA will not restart until it is reset. To reset,press the Reset button on the instrument’s backpanel.

If the power fail error code (“Err F02”) appearsat startup and remains even after you haveattempted to restart the instrument, the detectioncircuitry itself is probably at fault. Do not try torepair it yourself; call TA Instruments forservice.


The TMA instrument requires a normal linevoltage of 115 V AC, 50 or 60 Hz. Do notoperate it at less than 105 V AC or greater than130 V AC. Lower line voltage may result in poorinstrument operation; higher line voltage maydamage the instrument.

Diagnostics

ttttt CAUTION:



TMA 2940Test Functions

The TMA 2940 has three levels of test anddiagnostic functions:

• The confidence test that is run every timethe instrument is started.

• Cycling test functions that continuously testspecific.

• A manufacturing verifier test mode thatcoordinates and logs the results of asequence of confidence test and drift runs.

These test functions are always present in theinstrument. They are designed to aid manufac-turing and service in checking and repairing theinstrument.

The TMAConfidence Test

The TMA runs a confidence test every time it isstarted or reset. The confidence test checks mostof the computer and interface components in thesystem. Each of the tests that make up theconfidence test provides status and error infor-mation on the instrument display.

When the confidence test is running, a two-digithexadecimal test number is shown on the lowerright of the instrument display (see Figure 6.2).The number changes each time a new test isstarted. Most of the tests are performed veryquickly, so their test numbers may not beapparent.


Figure 6.2Instrument DisplayDuring the Confidence Test

The length of time required to run the confi-dence test depends on the options installed. Thebase level system takes about 12 seconds. Thelongest tests are the RAM tests, which takeabout 6 seconds.

After the tests are completed, a sign-on messageis displayed for three seconds. The system thenstarts normal operation, and the ready light onthe back of the TMA is turned on.


2940 TMA V1.0Confidence Test 00

TMA 2940 Test Functions



If an error is detected during the confidence test,an error message is posted on the bottom line ofthe instrument display. If the error is nonfatal,the program holds the error display for threeseconds and then goes on to the next test. If theerror is fatal, the error message is posted, andthe system halts. The ready light remains off. Afatal error means that a circuit essential to theoperation of the TMA has failed the confidencetest; the instrument cannot reliably perform anyfurther functions.

Table 6.1 summarizes the primary confidencetests for the TMA 2940.

Table 6.1Primary ConfidenceTest and ErrorCode Summary

Test Test FatalNumber (Y/N)

00 System failed start up Y30 CMOS RAM read/write test Y4n PROM checksum, location,

and version test Y5n CPU board I/O function tests Y6n Data storage memory

(DRAM) read/write test N70 GPIB communications test N82 Keypad shorted key test NAn Analog board tests NBn Motor drive board tests ND0 CMOS saved memory checksum test NE0 Fatal error while running Y


ReplacementParts

Tables 6.2 and 6.3 contain a list of the parts andthe part numbers associated with theThermomechanical Analyzer 2940.

Table 6.2Standard TMA Items

Part Number Description

944000.901 Automatic TMA

944004.001 Instruction Manual, TMA

944200.901 Standard TMA Accessory Kitconsisting of:

944122.901 (1) Expansion Probe Assembly

944126.901 (1) Penetration Probe Assembly944123.901 (1) Macro-Expansion Probe

Assembly944120.901 (1) Sample Stage944017.902 (1) Sample Thermocouple -

Type K with clip900902.901 (1) Indium Calibration Standard940070.000 (1) Aluminum Calibration Standard942057.000 (1) Teflon (R) Demonstration

Sample259537.000 (1) Forceps259522.000 (1) Set Weights203947.005 (1) 3/32 Hex Wrench269792.001 (2) Wave Washers944073.001 (1) Washer disc silicon

944072.001 (1) Reservoir mass aluminum

(table continued)

Replacement Parts



Table 6.3Optional Accessory Kits


944201.901 Film/Fiber Accessory Kitconsisting of:

944121.901 (1) Film/Fiber Sample Stage944128.901 (1) Film/Fiber Probe

Assembly941038.901 (1) Vial Cleaved Aluminum

Balls944047.901 (2) Film Clamp Assemblies944144.001 (1) Film Clamp Fixture269789.001 (1) Jeweler’s Screwdriver

(0.080 inch)269793.001 (10)Film Clamp Screws

(#0 - 80)

944202.901 Dilatometer Accessory Kitconsisting of:

944124.901 (1) Dilatometer ProbeAssembly

941143.000 (3) Dilatometer Sample Vials941148.000 (2) Vials Filling Medium941022.901 (1) Vial Aluminum

Calibration Standards

944203.901 Flexure Accessory Kitconsisting of:

944127.901 (1) Flexure Probe Assembly941054.000 (1) Flexure Sample Platform

(table continued)


Replacement Parts



944204.901 Parallel Plate RheometerAccessory Kit consisting of:

943147.901 (1) Rheometer Sample-Forming Die Set

943125.000 (3) Rheometer AlignmentCages

943126.000 (6) Rheometer Parallel Plates944125.901 Hemispherical Probe

Assembly944011.901 Heater Assembly for use

with the 2940 TMA

TA INSTRUMENTS TMA 2940 A–1

Appendix A: Ordering Information

For information or to placean order, contact:

United States:

TA Instruments, Inc.109 Lukens DriveNew Castle, DE 19720Telephone: (302) 427-4000 or (302) 427-4040Fax: (302) 427-4001

Overseas:

TA Instruments Ltd.Europe HouseBilton CentreCleeve RoadLeatherhead, Surrey KT22 7UQEnglandTelephone: 44-1-372-360363Fax: 44-1-372-360135

TA Instruments GmbHSiemenstrasse 163755 AlzenauGermanyTelephone: 49-6023-30044Fax: 49-6023-30823

TA Instruments BeneluxOttergemsesteenweg 461B-9000 GentBelgiumTelephone: 32-9-220-79-89Fax: 32-9-220-8321

Appendix A

A–2 TA INSTRUMENTS TMA 2940

TA Instruments JapanNo. 5 Koike Bldg.1-3-12 KitashinagawaShinagawa-Ku, Tokyo 140JapanTelephone: 813/3450-0981Fax: 813/3450-1322

TA Instruments France18 Rue Jean-BartParc D'Activities De La Grande Ile78960 Voisins-Le-BretonneuxFranceTelephone: 33-01-30489460Fax: 33-01-30489451

TA Instruments SpainAvienda Europe 21Planta Baja28100 AlcobendaMadrid, SpainTelephone: 34(9) 16618448Fax: 34(9) 16610655

For technicalassistance orservice in theUnited States:

HELPLINEFor technical assistance with current orpotential thermal analysis applications,please call the Thermal Analysis Help Deskat (302) 427-4070.

SERVICEFor instrument service and repairs,please call (302) 427-4050.

Printed in U.S.A.

TA INSTRUMENTS TMA 2940 I–1

Index

Index

A

accessories 1-12installation 4-5optional 1-13, 4-3setting up 3-17standard 1-12

expansion probes 1-12penetration probes 1-12

air cool 3-17automatic startup 3-17

air cool lineinstallation 2-25

aluminum balls 4-12

Auto Measure Offset 4-10, 4-11

Auto Measure Systemzeroing 3-12

B

balance enclosure 1-3installation 2-12removal 2-7

C

cablesinstallation 2-27

calculationsparellel plate thermal expansion

wall shear rate 4-43

calibration 3-7cell constant 3-9force 3-5probe 2-19, 3-7temperature.See Calibration:

temperature

calibration, displacementdilatometer accessory 4-21

clamps 4-14

cleaning 6-5keypad 6-5probe assembly 6-5stage 6-6thermocouple 6-7

coefficient of expansioncalculation 4-45, 5-5

components 1-3

Confidence test 6-12, 6-14failure 6-14numbers 6-14

confidence test 2-29

Index

TA INSTRUMENTS TMA 2940I–2

connecting cables 2-20

controllerkeyboard 1-7

D

diagnostics 6-9

die assemblyinstallation 4-32removal 4-31

Dilatometer Accessorybaseline calibration 4-24calibration 4-24, 4-25description 4-21, 4-23installation 4-23sample preparation 4-21, 4-26

display 1-7method status 1-7realtime signal 1-7sample temperature 1-7

E

equationscubic expansion 4-21loading 4-17sample tensile stress 4-4vial constant 4-22viscosity 4-46wall shear rate 4-46

error codesfatal 6-14nonfatal 6-14

experimentcooling type 3-22example 3-3, 3-16setting up 3-16startup 3-10, 3-20stopping 3-20

experimental procedure 3-10

F

Film/Fiber Accessory 4-4description 4-4installation 4-8operation 4-5sample preparation 4-12

Flexure Accessory 4-17description 4-17installation 4-18operation 4-17sample preparation 4-19

forcecalibration 2-8, 3-5

furnacecooling 3-22, 5-7function 1-9

furnace assembly 1-4

fuse 6-9location 6-9


Index

fusesFuse F1 6-9Fuse F2 6-9, 6-10

G

gasinput 3-18

gas linesinstallation 2-20

GPIBcable 2-20

H

HEATER on/off 1-11

HEATER Switch 1-11, 6-10

heater temperaturecalibration 3-8

Hemispherical Probe 4-47

I

inspection 2-9, 6-4

instrumentcabinet 1-3cleaning 6-5installing 2-9location 2-10power requirements 2-10repacking.See TMA 2940unpacking.See TMA 2940

Instrument Control 3-16

instrument control keys 1-8

instrument keypad.See TMA 2940:keypad

Instrument Parameters 4-41

Isolation Transformer 2-20, 2-27

K

key 1-9

L

LENGTH key 1-8

LVDTcalibrating 5-7

M

maintenance 6-4

Measure Length key 3-15

methodcreating 4-5, 4-23description 3-16segments 3-16selection 3-16

method status codes 5-7

Method status display 1-7

Index


moldable powders 4-35

O

offset 4-9

operating proceduresdilatometer accessory 4-21film/fiber accessory 4-5

P

Parallel Plate Rheometer 4-29cleanup 4-42operation 4-29sample loading 4-29sample preparation 4-29

part numbers 6-15

pellet press die setinstallation 4-34

power cableinstallation 2-26

power failures 6-10

POWER on/off 1-11

POWER Switch 1-11, 2-26

POWER switch 2-26, 2-29

probecalibration 3-6expansion

installation 2-18film/fiber

installation 4-7flexure 4-18

installation 4-7hemispherical 4-47installation 2-17, 2-18penetration

installation 2-18removal 2-19, 4-6selection 2-18, 3-11, 3-12setup

dilatometer 4-28fiber 4-13film 4-16film/fiber 4-7flexure 4-17, 4-20hemispherical 4-47

standard 1-12, 1-13, 2-18removal 2-19

types 3-11

probe assemblydescription 1-3

PROBE key 1-8

purgegases 3-18line 2-23rates 3-19system 3-18


Index

R

Realtime signaldisplay 1-7

REJECT 3-20

replacements 6-8

Reset button 2-22

resinous materials 4-38

S

sampleloading 3-13, 4-41measurement 3-15preparation 3-13

dilatometer accessory 4-26fiber 4-12films 4-15flexure accessoryspecifications 4-19moldable powders 4-35parallel plate rheometer 4-31resinous materials 4-38sheet materials 4-40

removal 3-20temperature

display 1-7thermocouple

cleaning 6-7function 1-4installation 6-8removal 6-8replacing 6-8

Sample Encapsulating Press 4-31description 4-31

SCROLL key 1-8

SCROLL-STOP key 3-20

sheet materials 4-40

specificationsphysical 1-14

spring clipinstallation 2-15removal 6-6

stage 1-3film/fiber

installation 4-8installation 2-14nut

installation 2-14removal 2-4, 2-6, 6-6

removal 4-6retainer ring 6-6

installation 2-14shield

installation 2-14, 2-16removal 6-6

START key 3-20

STOP key 3-20

subambient operation 3-22, 3-23

Index


T

technical specifications 1-14

temperaturecontrol 1-14, 1-15

thermocoupleattaching to stage 2-12, 2-16calibration 3-7cleaning 6-7, 6-8installing 2-8, 2-11positioning 3-15

Thermomechanical Analysis 5-4

TMA 2940accessory kit 1-12assembling 2-9assembly 1-3cabinet 1-3calibration 3-5.See also Calibra-

tioncleaning 6-5components 1-4confidence test 2-29, 6-13confidence tests 6-12description 1-3, 5-3display 1-7features 5-3flexure samples 4-19installation 3-4keypad 1-5maintenance 6-4part replacements 6-8parts list 6-15removing shipping material 2-6repacking 2-8shutting down 2-31

TMA 2940 (cont’d)specifications 1-14starting 2-29startup.See Startup: systemunpacking 2-3

TMA assemblybalance enclosure.See TMA

assemblyprobe assembly.See TMA assem-

bly

TMA Keypad 1-7

W

wave washerremoval 6-6

weight traydoor installation 2-13function 1-4

Z

Zero Length 4-19

ZERO LENGTH key 1-8, 3-12

tma 2940 operator's manual - tke · 2020. 7. 19. · ta instruments tma 2940 1–3...

Documents