hkpu 030124 - ir heat tracer

8/7/2019 HKPU 030124 - IR Heat Tracer

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Electrical Products Division

Application of NonApplication of Non--contact IR contact IR --Heat Tracer inHeat Tracer in

Maintenance and Repair OperationsMaintenance and Repair Operations

非触式紅外線溫度儀於修護工程之應用触式紅外線溫度儀於修護工程之應用

3 Electrical Products Division




Temperature Measuring TechniquesTemperature Measuring Techniques

Mercury thermometer

Thermistors – temperature sensitive resistors

Resistance temperature detector (RTD)

Thermocouples (Type J, T & K)

Solid state – e.g. P-N junction

Fibre optics (Raman effect/ OTDR)

Ultrasonic

Infrared thermometer (black body radiation)




What Is Infrared?

Infrared (IR) is that portion of theelectromagnetic spectrum that lies beyond

the visible response of the human eye. IR

wavelengths extend from 0.75 to 1000

microns.


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What Is Infrared?

All objects warmer than absolute

zero (0 K or -273°C) emit infrared

energy.

The hotter an object is, the more

active its molecules are, and themore infrared energy it emits.



Infrared ThermometersInfrared Thermometers

Provides a non-contact means of measuring the surface

temperature of an object safely

and accurately from a distance.



Reasons to Use Infrared for

Temperature Measurement

Non-contact, clean

Moving object

Inaccessible

Speed, reliability, repeatability

Real time measurement



About IR Heat Tracing

All objects that have temperatures above absolute zero radiate infraredenergy.

This energy travels in all directions at light speed

When pointed at a target, the lens of the Heat Tracer collects and focuses

the energy onto an infrared detector.

The detector responds by producing a voltage signal which is directly proportional to the amount of energy received, and a function of thetemperature of the target.

Some objects reflect as well as emit infrared energy.

Shiny or highly polished surfaces tend to reflect energy, whereas dullsurfaces do not.

Emissivity is a factor whose value ranges from 0.1 to 1.0, accounts for the actual energy being emitted.

Emissivity of different series Heat Tracers can be adjustable or pre-set.

Note: For almost all applications, the emissivity is set at 0.95, whichdescribes a target having a reflection of 5%.



How Do Infrared Thermometers Work?

An infrared thermometer house optics that

collect the radiant infrared energy being

emitted from an object and focus it onto a

detector.

The detector converts the energy into an

electrical signal, which is amplified anddisplayed.




What It Measures

R e f l ec t ed e n e rg

y

E mi t t e d e ne r g y

Transmitted

energy




ApplicationsApplications

Electrical MaintenanceElectrical Maintenance Locate over-temperature conditions caused by defective circuit

breakers, overload conditions or poor electrical connections

Monitor electric motors

Locate loose wire connections Diagnose nuisance tripping of circuit breakers

Locate defective ballasts within fluorescent fixtures

Food SafetyFood Safety

Audit storage temperature

Maintain process temperature

HouseholdHousehold

In the kitchen

In the garage

In the workshop





Mechanical Equipment MaintenanceMechanical Equipment MaintenanceMonitor furnace exteriors

Test heat exchangers, steam traps, air vents

Identify refrigeration problems

Check thermal insulation

Car/Truck/Fleet MaintenanceCar/Truck/Fleet Maintenance

Locate radiator core blockages

Identify misfiring spark plugs

Monitor electrical components

Diagnose low voltage batteries

TransportationTransportation

Monitor road surface temperature for icing conditions

Maintain asphalt temperature during preparation and application

A li i





Motor BearingMotor Bearing Hot Spot TracingHot Spot Tracing Elec. TerminalsElec. Terminals TxTx.. WingingsWingings

Overload/LooseOverload/LooseElec. ContactsElec. Contacts Performance AnalysisPerformance Analysis

Remote CircuitsRemote Circuits

Data LoggingData Logging




Selecting A Unit

Size of your target

Temp range of target

Distance to target

Surface of target

Data storage ability

Laser assisted sighting

Alarm requirement

Offset properties

D/S Ratio

Emisstivity settings




Measurement Spot Size

At 5 ft away 60:1 ratio1” spot

8:1 ratio7.5” spot




Distance To SpotDistance To Spot--size Ratiosize Ratio

Distance: Sensor to Object (mm)

Distance: Sensor to Object (inch)

S p o t D i a .

( m m )

S p o t D i

a .

( i n c h )




Distance To SpotDistance To Spot--size Ratio (Depth of Field)size Ratio (Depth of Field)




Field of View

Target size

too small

Target fall

into spot size




Emissivity

Emissivity is the ability of an object to emit

or absorb energy.

Perfect emitters have an emissivity of 1,

emitting 100% of incident energy.




Emissivity

Example, an object with an emissivity of

0.8 will emit 80% and reflect 20% of the

incident energy.

Unless you can adjust for emissivity, it is

difficult to take accurate readings of shinymetal surfaces.




Typical Emissivity Values

NonNon--MetalMetal




Determine an Unknown SurfaceDetermine an Unknown Surface EmissivityEmissivity

Compare with a thermo-couple.

Using masing tape with emissivity of 0.95

Drill a hole approximately (3.5 cm) in diameter

and approximately (10 cm) deep in a sample of the object. This hole will act as a blackbody

with emissivity of approximately 0.97.

Paint it with a flat black paint. These materials

exhibit an emissivity of approximately 0.95.

A Typical Temperature Profile of anA Typical Temperature Profile of an




A Typical Temperature Profile of anA Typical Temperature Profile of an

induction Heating Processinduction Heating Process




What Does Specification Tells You?

IR-750C IR-750CL2 IR-750CEXL2 IR-60L2 IR-60EXPL2

TTeemmpp -32°C-

400°C

-32°C-

400°C-32°C-500°C -32°C-870°C -32°C-870°C

LLaasseerr √ √ √

CIRCULAR

√

CIRCULAR

DD::SS R R aattiioo 8:1 8:1 8:1 60:1 60:1

HHii AAllaarrmm √ √ √

LLoo AAllaarrmm √ √

AAdd j juusstt EEmmiissss..

√ √ √

SSttoorree ddaattaa √




Laser Classes

Class I Lasers

These are lasers that are not hazardous for continuous viewing or are

designed in such a way that prevent human access to laser radiation.

These consist of low power lasers or higher power embedded lasers. (i.e.laser printers)

Class 2 Visible Lasers (400 to 700 nm)

Lasers emitting visible light which because of normal human aversion

responses, do not normally present a hazard, but would if viewed directlyfor extended periods of time. (like many conventional light sources)

Class 2A Visible Lasers (400 to 700 nm)

Lasers emitting visible light not intended for viewing, and under normaloperating conditions would not produce a injury to the eye if viewed directly

for less than 1000 seconds. (i.e. bar code scanners)




Laser Classes

Class 3a

Lasers that normally would not cause injury to the eye if viewed

momentarily but would present a hazard if viewed using collecting optics

(fibre optics loupe or telescope).

Class 3b

Lasers that present an eye and skin hazard if viewed directly. This includes

both intrabeam viewing and specular reflections. Class 3b lasers do notproduce a hazardous diffuse reflection except when viewed at close

proximity.

Class 4 Lasers

Lasers that present an eye hazard from direct, specular and diffuse

reflections. In addition such lasers may be fire hazards and produce skin

burns.




Laser Energy Effects On The Eyes

Wavelength

Incident or reflected laser beam:

• Laser light in the visible to near infrared

spectrum (i.e., 400 - 1400 nm) can cause

damage to the retina (视网膜) resulting inscotoma (blind spot in the fovea).

• Laser light in the ultraviolet (290 - 400 nm) or

far infrared (1400 - 10,600 nm) spectrum can

cause damage to the cornea (角膜) and/or to

the lens.




Selecting A Unit

Size of your target

Temp range of target

Distance to target

Surface of target

Data storage ability

Laser assisted sighting

Alarm requirement

Offset properties

D/S Ratio

Emisstivity settings

A supplier that can support you on your applications A supplier that can support you on your applications

hkpu 030124 - ir heat tracer

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