spectrophotometer operatonal manual v 1.0 revision 1
TRANSCRIPT
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SPECTROPHOTOMETER
OPERATONAL MANUAL
V 1.0
Revision 1
For Alpha-1101, 1102, 1502
Laxco, Inc.
www.laxcoinc.com
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TABLE OF CONTENTS
General information ........................................................................................................................ 3 Safety ...................................................................................................................................... 3 Electrical ................................................................................................................................. 3 Warning................................................................................................................................... 3 Performance ............................................................................................................................ 3 Radio Interference ................................................................................................................... 4 Introduction ............................................................................................................................. 4 Working Principle ................................................................................................................... 4 Unpacking Instructions ........................................................................................................... 5 Specifications .......................................................................................................................... 5 Installation: ............................................................................................................................. 5 Operational Panel .................................................................................................................... 7
Description of Keys ................................................................................................................ 7 Operation Instruction: ..................................................................................................................... 8
Prepare the spectrophotometer ................................................................................................ 8
BASIC MODE ━ %T/Abs Measure ...................................................................................... 9
Quantitative Test ................................................................................................................... 11 Run test ......................................................................................................................... 11 All Test List .................................................................................................................. 12 Define a un-defined test in All Test List ....................................................................... 13
By Known Factors ................................................................................................ 13 By Standard ........................................................................................................... 16
UTILITY ............................................................................................................................... 18 Wavelength Calibration ................................................................................................ 18 Collecting Dark Current ................................................................................................ 19
Edit Clock ..................................................................................................................... 19 System Baseline ............................................................................................................ 20 Turn on/off Deuterium Lamp........................................................................................ 20 Turn on/off Tungsten Halogen Lamp ........................................................................... 20 Reset Defaults ............................................................................................................... 20
Memory Manager.......................................................................................................... 20 Wavelength Correction ................................................................................................. 21
PC LINK ............................................................................................................................... 22 Wavelength Calibration: ............................................................................................................... 22
Holmium Oxide Filter Method: ............................................................................................ 23
Didymium Filter Method: ..................................................................................................... 23 Absorbance Accuracy Checks ...................................................................................................... 24
Stray Light Check ......................................................................................................................... 25 Trouble Shooting: ......................................................................................................................... 25 Error Codes Definitions: ............................................................................................................... 27
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General information The apparatus described in this manual is designed to be used by properly trained personnel
in a suitable equipped laboratory. For the correct and safe use of this apparatus it is essential that
laboratory personnel follow generally accepted safe procedures in addition to the safety
precautions called for in this manual.
The covers on this instrument may be removed for servicing. However, the inside of the
power supply unit is a hazardous area and its cover should not be removed under any
circumstances. There are no serviceable components inside this power supply unit. For all
instruments, avoid touching the high voltage power supply at all times.
Some of the chemicals used in spectrophotometry are corrosive and/or inflammable and
samples may be radioactive, toxic, or potentially pathogens. Care should be taken to follow the
normal laboratory procedures for handling chemicals and samples.
Safety Read the following before installing and using the instrument and its accessories. The
instruments mentioned in this manual should be operated by appropriate laboratory technicians.
Electrical The power cord shall be inserted in a socket provided with a protective earth contact. The
protective action must not be negated by the use of an extension cord without a protective
conductor.
Warning Any interruption of the protective conductor inside or outside the apparatus or disconnection
of the protective earth terminal is likely to make the apparatus dangerous. Intentional
interruption is prohibited.
Whenever it is likely that the protection has been impaired, the apparatus shall be made
inoperative and be secured against any unintended operation. NEVER touch or handle the power
supply on the Alpha-1502 due to the high voltage.
The protection is likely to be impaired if, for example, the apparatus
Shows visible damage
Fails to perform the intended measurements
Has been subjected to prolonged storage under unfavorable conditions.
Has been subjected to severe transport stresses
Performance To ensure that the instrument is working within its specification, please verify proper
operation before making important measurements, carry out performance checks for this
particular reference to wavelength and absorbance accuracy. Performance checks are detailed in
this manual.
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Radio Interference For compliance with the EMC standards referred to in the EC Declaration of Conformity, it
is necessary that only shielded cables supplied by the factory be used when connecting the
instrument to computers and accessories.
Introduction The Alpha series are single beam, general purpose instruments designed to meet the needs of
the Conventional Laboratory. They are ideal for various applications, such as: Clinical
Chemistry, Biochemistry, Petro chemistry, Environmental Protection, Food and Beverage Labs,
Water and Waste Water Labs and other fields of quality control and research.
The Alpha Series features a LCD display of photometric result, easy operation and
wavelength range of 325nm to 1000nm (200-1000nm for Alpha-1502), these instruments are
ideal for measurements in the visible wavelength region of the electromagnetic spectrum,
(ultraviolet and visible for the Alpha-1502).
Working Principle The spectrophotometer consists of five parts: 1) Halogen and deuterium if Alpha-1502, lamp
to supply the light; 2) A Monochromator to isolate the wavelength of interest and eliminate the
unwanted second order radiation; 3) A sample compartment to accommodate the sample
solution; 4) A detector to receive the transmitted light and convert it to an electrical signal; and
5) A digital display to indicate absorbance or transmittance. The block diagram below illustrates
the relationship between these parts.
Block diagram for the Spectrophotometer
In your spectrophotometer, light from the lamp is focused on the entrance slit of the
monochromator where the collimating mirror directs the beam onto the grating. The grating
disperses the light beam to produce the spectrum, a portion of which is focused on the exit slit of
the monochromator by a collimating mirror. From here the beam is passed to a sample
compartment through one of the filters, which helps to eliminate unwanted second order
radiation from the diffraction grating. Upon leaving the sample compartment, the beam is passed
to the silicon photodiode detector and causes the detector to produce an electrical signal that is
displayed on the digital display.
The Alpha Series incorporates an USB1.0 for connecting to a PC via the Application
Software and a RS232 port for the built-in thermal printer.
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Unpacking Instructions
Carefully unpack the contents and check the materials against the following packing list to
ensure that you have received everything in good condition:
Packing List
Description: Quantity
Spectrophotometer...........……................. ….......................... .. 1
Power Cord…………………………………....…......……….. 1
Cuvettes..................................……............... …........……….. Set of 4, glass
Set of 2, quartz (Alpha-1502 only)
Operational Manual................................................………......... 1
Dust Cover……………………………………………………... 1
Specifications
Alpha-1101 Alpha-1102 Alpha-1502
Wavelength Range 325-1000nm 200-1000nm
Spectral Band pass 4nm
Wavelength Accuracy +2 nm
Wavelength
Repeatability ≤1nm
Stray Radiant Energy ≤0.1@ 360 and 400nm ≤0.1 @ 220 and 340nm
Photometric Range 0 to 125%T -0.3 to 2.5 Abs -9999 to 9999
Photometric Accuracy ±0.5%T(0~100%T)
Data output USB1.0 and Optional Built in Printer
Power Requirements 85-240Vac, 50-60 Hz
Dimensions 450W x 370D x 200H 570W x 460D x 230H (mm)
Light Source Tungsten Halogen Tungsten
Halogen/Deuterium
Weight 8kg 13.5kg 14.2kg
Installation:
1. After carefully unpacking the contents, check the materials with the packing list, this page, to
ensure that you have received everything in good condition.
2. Place the instrument in a suitable location away from direct sunlight. In order to have the best
performance from your instrument, keep it as far as possible from any strong magnetic or
electrical fields or any electrical device that may generate high-frequency fields. Set the unit up
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in an area that is free of dust, corrosive gases and strong vibrations.
3. Remove any obstructions or materials that could hinder the flow of air under and around the
instrument.
4. Turn on the instrument and allow it to warm up for at least 15 minutes before taking any
readings.
Back View of Alpha-1502
Power Cord Inlet
On/Off Switch
Light View hole
Air Vent
USB1.0 Cooling Fan
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Operational Panel
Description of Keys
【CLEAR/LOAD】 Clear number or character in edition in Quantitative
Mode, Load data or curve saved before;
【PRINT/SAVE】 Print data , Save data or curve;
【0Abs/100%T】 Set 0Abs and 100%T;
【EXIT】 Exit to previous screen;
【ENTER】 Confirm the inputted data or selected item; Go to next
setup or screen;
WL/Conc./F
【∧】,【∨】 Set Wavelength, Standard solution value and Standard
solution Factor value;
Menu Scroll
【∧】,【∨】 Browse the items in the menu
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Operation Instruction:
Prepare the spectrophotometer
Turn on the spectrophotometer by pressing the Power Switch (IO). The screen displays
sequentially as Fig 6. Pressing EXIT or after 15 minutes warm up, the instrument will locate
lamp(Alpha-1502) and filter, then main menu displays as Fig 7.
Fig 6
Note: By different mode, the second line display in Fig 6 may be “Alpha-1102” or
“Alpha-1502”
Fig 7
Note: a. If the saved wavelength has been out of order, “WL calibrating” will be
implemented and then will go into Main Menu.
b. It is strongly recommended that taking dark current measurements following the
steps below after warm-up.
b. 1 Select UTILITY in Fig 7 and then select Dark Current in Fig 8.1
Fig 8.1
b. 2 Dark Current will be taken shown as Fig 8.2 and be saved shown as Fig
8.3 after pressing EXIT
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Fig 8.2
Fig 8.3
BASIC MODE ━ %T/Abs Measure
1. In Fig 7, scroll * to BASIC MODE and then press ENTER to Select basic T/Abs mode.
Showed as Fig 9.If the readouts are not 100.0%T and 0.000A, you may press
0Abs/100%T to blank.
Fig 9 BASIC MODE
2. Select the desired wavelength by pressing the appropriate key. At any time that the
wavelength is changed, blank will automatically be implemented showed as Fig 10.1,Fig
10.2 and 10.3
Fig 10.1 Select the wavelength before you confirmed
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Fig 10.2 Select the wavelength after you confirmed
Fig 10.3 Blank automatically
Note: Pressing WL/Conc./F 【∧】,【∨】, the wavelength changes at 1nm ,
Pressing Menu Scroll 【∧】,【∨】,the wavelength changes at 20 nm interval.
3. Make a blank reference solution by filling a clean cuvette (or test tube) half full with
distilled or de-ionized water or other specified solvent. Wipe the cuvette with tissue to
remove the fingerprints and droplets of liquid.
4. Fit the blank cuvette into the 4-cell linear stage and place the cuvette in the slot nearest
you. Push the stage so that the cuvette is in the light path (Push the rod in). Close the lid.
5. Set 0.000A or 100%T with the (0A/100%T) control key.
6. Remove the blank cuvette if you are testing more than 3 samples. Set it aside in the case
that you may need to adjust the (0A/100%T) control key later (i.e. change the
wavelength).
7. Rinse a second cuvette (or more) with a small amount of the sample solution to be tested.
Fill the cuvette half full and wipe it.
8. Put the sample cuvette(s) in the sample compartment. Close the lid.
9. Read the % Transmittance and Absorbance from the LCD readout window. If you are
reading more than one cuvette, be sure to carefully move the stage to the next position by
pulling on the sample holder knob until you feel the holder “click” into place. Be sure to
make note of the readout (or print) for each sample. Remove the sample cuvette(s).
Operational Note:
a. if you are reading 3 or less samples, then place the reference cuvette in the position
nearest you, and the samples in the next available position. This will shorten the time to
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read samples and minimize the sample handling (opening and closing the sample
compartment lid, etc.)
b. If you are saving or printing the readings, please press PRINT/SAVE and follow the
instruction on line 4 of screen.
10. If you are to test the same sample at other wavelengths, repeat steps 2 to 10 for each
wavelength.
11. For each new sample you analyze, repeat steps 3 to 9.
Quantitative Test In Fig 7 Scroll * to Quantitative and then press ENTER to Select Quantitative Test
mode, showed as Fig 11.
Fig 11
Run test
Select Run Test in Fig 11 to enter a saved tests list shown as Fig 12.
Fig 12
Scroll * to the left of desired test and then press ENTER to confirm. Let’s take the “COBALT”
for example, the screen displayed as Fig 12.1, Fig 12.2 and Fig 12.3
Usually you should place the reference cuvette in the slot nearest you and place the sample
cuvette in the another slot, blank to reference by pressing 0Abs/100%T and take readings shown
as Fig 13 after putting the sample cuvette to light path.
Fig 12.1 goes to preset wavelength
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Fig 12.2 Blank automatically
Fig 12.3 After Blanking
Fig 13 Test result readings
NOTE: a. You can delete a test in Fig 12 by scrolling * to the left of its name and pressing
CLEAR/LOAD. Also you can add a test to the list in Fig 12, please refer to All Test
List.
b. If you are saving or printing the readings, please press PRINT/SAVE and follow the
instruction on line 4 of screen.
All Test List
Select All Test List in Fig 11 to enter ,All test list shown as Fig 14.
Fig 14
There are 200 un-defined tests listed in All Test List.
You can add a test in All Test List to Run Test menu by scrolling * to the left of its name
and pressing CLEAR/LOAD.
Note: You can’t run any test in All Test List, only in Run Test menu.
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Define a un-defined test in All Test List
The 200 un-defined tests are originally named “To be defined 001-200”,It will be possible to
rename the test by selecting wavelength, entering a new calibration and curve fitting option of
linear least squares or least squares through zero.
In Fig 14, scroll * to the left of desired to rename test and press ENTER to confirm, the Fig
15 appear. Let’s take “To be defined 02” for example:
Fig 15
If you have a calibrated test to define, please select “By Known Factors”. If you are
calibrating curve whose standard concentrations are between 1 and 8 data points, please select
“By Standard”.
By Known Factors
There are seven items for selection, shown as Fig 16.
Item1: Wavelength may be selected by pressing WL/Conc./F 【∧】,【∨】.
After confirm by pressing ENTER, screen return to previous menu and the * move to
item2 automatically.
Item2: Then concentration unit may be selected by pressing Menu Scroll 【∧】,【∨】.
After confirm by pressing ENTER, screen return to previous menu and the * move to
item 3 automatically.
Fig 16
Item3: Fitness method may be selected by pressing Menu Scroll 【∧】,【∨】.After
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confirm by pressing ENTER, screen return to previous menu and the * move to item4
automatically.
Item4: After ENTER is pressed, the screen displayed as Fig 17
Fig 17
On the assumption that the curve is expressed as:
Concentration = Intercept+ Slope*Absorbance; one order linear.
Concentration = Slope*Absorbance; one order linear through zero.
Let’s input Intercept=1.058
Press Menu Scroll【∨】to scroll right to number 1. Selection of number is controlled
by moving the flashing cursor over top of the number to be chosen. The Menu Scroll【∧】
scroll left. Press the Menu Scroll【∨】scroll right. Press WL/Conc./F 【∧】with the
flashing cursor over the number 1 to select it. The number 1 will appear now in line 3 next to =.
Continue in this fashion until entire 1.058 is entered. Showed as Fig 18
Fig 18
Press CLEAR/LOAD to delete/erase any incorrect entry.
Press WL/Conc./F 【∨】to alter the polarity of the number.
Press ENTER to finish entry and screen is displayed as Fig 19
Fig 19
Input Slope=2.588, the way is just like the entry of intercept.
After confirm by pressing ENTER, screen return to previous menu and the * move to item5
automatically.
Note: If you select “Liner through 0” in Item3, no intercept may be entered.
Item5: After ENTER is pressed, the screen displayed as Fig 20
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Fig 20
The entry of characters is the same as the entry of intercept and slope. After
BROMINE LR is entered, the screen is displayed as Fig21:
Fig 21
Press ENTER to go back to previous menu and the * move to item6 automatically.
Item6:The defined test/curve may be saved by pressing ENTER, after saved screen return to
previous menu and the * move to item7 automatically.
Item7:Pressing ENTER to display and print(if printer is connected) the test, the test number
(N0.=002),wavelength(581nm),test name(BROMINE LR), Fitness method(1 represent
“one order linear”, 2 represent“ one order linear through zero”, intercept(1.058),
slope(2.588) and concentration unit (ppm) are all included. Shown as Fig 22, any
incorrect entry may be checked with this item.
Fig 22
Note: Here N and M have no meaning.
Now all definitions to test 002 have been finished, press EXIT to return to All Test List
menu, the “To be defined 002” has been replaced with “BROMINRE LR ”. Shown as Fig
23.
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Fig 23
By Standard
There are nine items for selection, shown as Fig 24.
Item1: The same operation as in By Known Factors;
Item2: The same operation as in By Known Factors;
Item3: Selection of how many data points which be used for standard curve establishing,
the maximum is eight points.
Item4: Selection of how many times measurement to one standard concentration sample;
Item5: The same operation as in By Known Factors;
Fig 24
Item6: After Measure Standard is selected, the screen is displayed as Fig 25
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Fig 25
Place reference solution cuvette in sample compartment, press 【0Abs/100%T】. The Fig
26 appears after the Blank finishes;
Fig 26
On the assumption that 3 standard solution (data points) are measuring. Place all 3 sample
solution cuvettes in compartment and pull standard solution No.1 to light path.
Enter the value of standard solution No.1 like the operation of intercept Entry in By Known
Factors. Press ENTER, the Absorbance vs. Standard solution No.1 will be measured and
displayed as Fig 27.
Fig 27
If you set the replicas, No=3 in item4, Press ENTER second time, standard solution No.1
will be measured again and the screen display 0.18775A2,press ENTER third time, display as
0.1876A3,press ENTER fourth time, display as 0.1876A, so we have get the Absorbance vs.
Standard solution No.1 0.1876A that is from (0.1877A1+0.1875A2+0.1876A3)/3.
If you have 3 standard solutions available, please pull standard solution No.2 and No.3 to light
path. Repeat the operation above; after you finish measurement to all 3 standard solution, the
screen is displayed as Fig 28.
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Fig 28
After pressing ENTER, the screen goes back to previous menu,
Note: You may view the created curve in Item 9 (Dis. & Print Curve)
Item7: The same operation as in By Known Factors;
Item8: The same operation as in By Known Factors;
Item9: The same operation as in By Known Factors;
UTILITY
A few specific functions can be set in UTILITY menu.
In MAIN MENU (Fig 7), move * down to the left of UTILITY and press ENTER to go into
UTILITY menu, shown as Fig 29
Fig 29
There are 9 items listed in UTILITY menu.
Wavelength Calibration
Item1: After selecting WL Calibration, the instrument will implement a self testing procedure; it
contains filter locating check, lamp locating check and wavelength calibrating.
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Collecting Dark Current
Item2: Dark Current is designed to eliminate the error from the light source and electronic parts
drifting. It is recommended that you refresh and save the Dark Current by selecting this
Item after 15 minutes warm up;
Edit Clock
Item3: In Edit Clock menu, there 3 sub-items are listed, Fig 30.
Set Clock
Select Set Clock in Fig 30, displayed as Fig31. If any require changing, press ENTER to
cycle through Set Week, Set Year, Set Month, Set Day, Set Hour, Set Minute, Set Second, until
required one is displayed on Line3. Press WL/Conc./F 【∧】【∨】to change. Press ENTER to
confirm. Press EXIT back to Fig 30.
Fig 30
Fig 31
Select Display of Date or Time
Select Display Mode in Fig 30, displayed as Fig32. Press Menu Scroll 【∧】【∨】to
select Display Time or Display Date. Press ENTER to confirm. Press EXIT back to Fig 30.
Fig 32
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System Baseline
Item4: System Baseline is used for determining the appropriate energy level which cover all
wavelength range 324vnm to 1000vnm for Alpah-1101 and Alpha-1102 and 204 nm to
1000 nm for Alpha-1502. Fig 34 shows the procedure of establishing system baseline.
Fig 34
Turn on/off Deuterium Lamp
Item5: Turn on/off D2 The deuterium lamp (D2)energy decreases with time, so if wavelength
200 to 340 are not being used, it is advisable to turn off deuterium lamp. This item is
designed for this demand.
Turn on/off Tungsten Halogen Lamp
Item6: Turn on/off Tungsten Halogen Lamp. The Tungsten Halogen lamp (W) energy decreases
with time, so if wavelength 340 to 1000 are not being used, it is advisable to turn off
deuterium lamp. This item is designed for this demand.
Reset Defaults
Item7: Reset Defaults is designed for future application;
Memory Manager
Item8: Select Memory Manager to go into next screen, shown as Fig 35. There are 3 sub-items
listed.
Fig 35
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Load Saved data
Select Load Saved data in Fig 35, the saved data will list all as Fig36.
Fig 36
With * next to COBALT, press ENTER, you can print the data (if printer installed) and display it
on screen, or you can send the data to computer shown as Fig 37.
Fig 37
Clear User Tests
Select Clear User Tests in Fig 35, all established and saved tests/curves will be deleted.
Please be careful for this choice.
Clear Data Memory
Select Clear Data Memory in Fig. 35. All saved tests data will be deleted. Please be careful
for this choice.
Wavelength Correction
Item9: If, after WL Calibration, it is found that the holmium specific peak is not in the correct
position, this item can be used to change it. Select WL Correction in Fig 29 to go into Fig
38.
Fig 38
Press WL/Conc./F 【∧】【∨】to make choice.
Press ENTER to confirm.
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Press EXIT back to previous menu.
Note: WL Correction was done at the factory. It is not recommended for customer to do it.
The corrected WL will be saved in memory and will be held after power off.
PC LINK
Alpha-1101, Alpha-1102 and Alpha-1502 are designed to be operated by Computer with
the application software. In fig 7, move * to the left of PC LINK and press ENTER, the screen is
displayed as Fig 39.
Fig 39
After it finishes handshaking with PC, the screen is displayed as Fig 40. Please refer to the
application software manual for detailed.
Fig 40
Wavelength Calibration:
Normally, the Alpha-1101, Alpha-1102 and Alpha-1502 Series spectrophotometer retains its
wavelength calibration indefinitely. However if the instrument receives a severe shock or is
abused, use the following methods to check wavelength calibration. Please note that this test
requires the use of a Didymium filter, or the Holmium Oxide filter.
In the filter method, the didymium filter has two distinct absorbance peaks at 529nm and 807nm.
The Holmium filter has a distinct peak at 361nm. When the instrument is calibrated properly
you will find minimum Transmittance (maximum Absorbance) at the range +2nm from these
peaks. Note that the specific Transmittance values are not important as you are only looking for
the wavelength where the minimum transmittance (maximum Absorbance) occurs.
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Holmium Oxide Filter Method:
1. Turn instrument on and allow it to warm up for 15 minutes.
2. Select the BASIC MODE.
3. Set the wavelength to 350nm.
4. Make sure the cuvette holder is empty in the sample compartment. Close the sample
compartment lid.
5. Set zero Absorbance by pressing the 0A/100%T. The reading should then be 0.000A. If not,
press 0Abs/100%T again.
6. Remove the cuvette holder and insert the Holmium filter into it. Place it in the sample
compartment and close the lid.
7. Record the Absorbance reading on the LCD display.
8. Advance the wavelength setting by 1nm and repeat steps 2 to 5.
9. Repeat step 6 until the wavelength setting reaches 370nm.
10. Look for the maximum absorbance reading obtained, and this should be found between 359
and 363nm.
Didymium Filter Method:
1. Set the Wavelength to 800 nm.
2. Make sure the cuvette holder is empty in the sample compartment. Close the sample
compartment lid.
3. Set zero Abs by pressing the 0A/100%T. The reading should then be 0.000A. If not, press
0Abs/100%T again.
4. Remove the cuvette holder and insert the Didymium filter into it. Place it in the sample
compartment and close the lid.
5. Record the Absorbance reading on the LCD display.
6. Advance the wavelength setting by 1nm and repeat steps 2 to 5.
7. Repeat step 6 until the wavelength setting reaches 815nm.
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8. Look for the maximum absorbance reading obtained, and this should be found between 805
and 809nm.
9. If a “middle” wavelength check is desired, set the wavelength to 522nm (optional)
10. Make sure the cuvette holder is empty in the sample compartment. Close the sample lid.
11. Set zero Abs by pressing the 0A/100%T key. The reading should then be 0.000A .If not,
press 0Abs/100%T again
12. Remove the cuvette holder and insert the Didymium filter into it. Place it in the sample
compartment and close the lid.
13. Record the absorbance reading on the LCD display.
14. Advance the wavelength setting by 1nm and repeat steps 10 to 13.
15. Repeat step 14 until the wavelength setting reaches 536nm. Again, look for the maximum
absorbance reading. It should be between 527 and 531nm.
Absorbance Accuracy Checks
Specification: +0.004A at 0.5A.
The absorbance accuracy should be checked against a set of neutral density filters accurately
calibrated to the NIST standards. Contact your factory representative for more information.
An alternative method using potassium dichromate is described below. Due to the many factors
that might affect the results (i.e. temperature, band pass, weighing and diluting errors), this
method is less accurate and should only be used as a guide.
1. Make up N/100 sulfuric acid as the solvent and use part of it to make a solution
containing 120 +0.5mg/liter of potassium dichromate.
2. Wash out a square cuvette with solvent, and fill with solvent.
3. Put the cuvette into the sample compartment and close the lid.
4. Select BASIC MODE and Set the wavelength to 350nm.
5. Set the reading to 0.000A using the 0Abs/100%T key.
6. Empty the cell. Wash out with dichromate solution, and fill with dichromate solution.
7. Put the cuvette into the sample compartment and close the lid.
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8. Read the absorbance of the standard from the LCD display. The value should be
Calibrated Value + 0.004A. Refer to the notes above when interpreting the result.
Note: It is recommended that you refresh the Dark Current setting (refer to Page19).
Stray Light Check
Specification: ≤ 0.1%T at 360 nm and 400 nm (Alpha-1101,1102); ≤0.1 %T at 220 and 340 nm
(Alpha-1502)
A good indication as to whether the stray light level is within specification may be obtained as
follows:
1. Set the wavelength to 340nm.
2. Select BASIC MODE with the sample compartment empty, close the lid and press the
0A/100%T key to set the LCD display to 100.0%.
3. Prepare a solution containing 50gm/L of sodium nitrite (NaNO2) in distilled water and fill
a square cuvette with this solution.
4. Place the cuvette in the sample compartment. Close the lid. The display should read
≤0.1%T.
Note: It is recommended that you refresh the Dark Current setting (refer to Page19).
Trouble Shooting:
PROBLEM Possible Solution
Instrument Inoperative Power cord not connected to
outlet
Plug instrument in.
Dead Power outlet Change to a different outlet
Internal fuse blown or
defective electronic component
Call an authorized service engineer.
Improper power setting Set to the main power
Instrument cannot set
100%T (0.000A)
Light beam blocked Check sample holder. See if holder is
properly positioned and nothing is blocking
light path.
Lamp is misaligned. Check to see if light is positioned properly on
entrance slit to monochromator. Call
Technical Service for details.
Defective electronic
component.
Call an authorized service engineer.
Incorrect
Transmittance to
Bubbles or particles in
solution.
Check sample preparation and analytical
procedure.
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Absorbance correlation
Defective electronic
component.
Call an authorized service engineer.
LCD Digital Display
does not change
regardless of sample
concentration
Concentration reading
“frozen”.
Sample Solution too Dark , dilute it and
Restart measurement procedure.
Wrong wavelength setting. Check sample procedure and wavelength
setting.
Insufficient sample volume. Fill cuvette with more sample.
Stray sample preparation
vapors.
Prepare the sample away from the
instrument. Use proper ventilation.
Bubbles or particles in
solution.
Check sample preparation and analytical
procedure.
Defective electronic
component or loose wiring.
Call an authorized service engineer.
Instrument drift and
noise
Lamp not adjusted properly. Check lamp has been properly installed or
has moved during transit.
Lamp old or defective. Replace with a new lamp.
Defective or dirty detector or
defective electronic
component.
Call an authorized service engineer.
Incorrect readings
obtained
Insufficient sample volume Fill cuvette with more sample.
Wrong wavelength setting. Check analytical procedure and wavelength
setting. Check wavelength accuracy
according to procedure in this manual.
Stray sample preparation
vapors.
Prepare sample away from instrument. Use
proper ventilation.
Bubbles or particles in
solution.
Check sample preparation and analytical
procedure.
Instrument out of electronic
calibration.
Call an authorized service engineer.
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Error Codes Definitions:
The Error Codes are the classification for errors detected automatically by the instrument. Each code
represents different errors that occur during the self-calibration or during operation. The Error Codes are
displayed on the wavelength display and are defined as follows:
Error Code Definition (function) Causes/Solutions
Error 1 Instrument unable to
initialize and/or locate the
lamp (Alpha-1502only).
Check power supply to see if proper voltage is
selected.
Open cover of instrument and check the connector
J12 between CPU board and Lamp-change-over
motor .
Lamp-change-over motor or lamp initialization
switch malfunctioning. Check the connector J13 on
CPU board.
Call authorized service engineer
Error 2 Instrument unable to
initialize and/or locate the
filter
Open cover roof instrument and check the connector
J4 between CPU board and Filter-driven motor.
Filter-driven motor malfunctioning. Check the
connector J2 on CPU board.
Call authorized service engineer
Error 3 Monochromator unable to
locate starting position Monochromator contact switch or grating-driven
motor (WL motor) is malfunctioning
Open cover of instrument and check the connector J3
between CPU board and grating-driven motor.
Check the connector J5 on CPU board
Call authorized service engineer.
Error 4 Instrument unable to locate
“0” order light
Check sample holder. See if holder is properly
positioned and nothing is blocking light path.
Check to see if light is positioned properly on
entrance slit to monochromator.
Check tungsten-halogen lamp. Replace lamp if
necessary.
Call authorized service engineer.
Error 5 Instrument is unable to set
0A/100%T.“Energy
Low!” display.
Check sample compartment and remove cuvette or
any object blocking light path.
Place the 4-cell sample holder in the proper position.
See if the lamps is ON or OFF via the small hole in
the rear of the instrument. If OFF, call authorized
service engineer.
Contact an authorized service engineer.