Noncontact Temperature Measurement€¦ · Noncontact Temperature Measurement Manual 57560-1 Rev A...

Noncontact Temperature Measurement

Manual

57560-1 Rev A West 11/02

■ Infrared Thermometer for Automotive Diagnostics

■ Infrarot-Thermometer für die Fahrzeugdiagnose

■ Termômetro Infravermelho para Diagnósticos Automotivos

■ Termómetro Infrarrojo para Diagnóstico Automotriz

■ Thermomètre infrarouge pour le diagnostique automobile

1.888.610.7664 [email protected]

Worldwide HeadquartersRaytek Corporation1201 Shaffer Rd. PO Box 1820Santa Cruz, CA 95061-1820 USA Tel: 1 800 866 5478

1 831 458 1110Fax: 1 831 425 [email protected]

Raytek China Company Beijing, ChinaTel: 86 10 6439 2255 Fax: 86 10 6437 [email protected]

Raytek Japan, Inc. Osaka, JapanTel: 81 6 4390 5015Fax: 81 6 4390 [email protected]

South American HeadquartersRaytek do BrasilSorocaba, SP BrasilTel: 55 15 32176046Fax: 55 15 [email protected]

European HeadquartersRaytek GmbHBerlin, GermanyTel: 49 30 4 78 00 80Fax: 49 30 4 71 02 [email protected]

Raytek UK Ltd.Milton Keynes, United KingdomTel: 44 1908 630800Fax: 44 1908 [email protected]

Raytek FrancePalaiseau, FranceTel: 33 1 64 53 15 40Fax: 33 1 64 53 15 [email protected]

Worldwide ServiceRaytek offers services including emergency repairs and calibration. For more information, contact your local office or e-mail:[email protected]

www.raytek.comfor up-to-the-minute features


500 mSec (95% of reading) 8-14µm

Pre-set at 0.950 to 50ºC (32 to 120ºF)

10-90% RH noncondensing, at 30 to 50ºC (86 to 122ºF)

-20 to 60ºC (-13 to 158ºF) without battery360g (12oz) 205 x 160 x 55mm (8x6x2 in)

9V Alkaline or NiCd Battery4 hrs w/laser, flashlight & backlight on20 hrs w/laser, flashlight & backlight off

Response Time Spectral ResponseEmissivityAmbient Operating Temp.Relative Humidity

Storage TemperatureWeight/DimensionsPower Typical Battery Life (Alkaline)

Specifications

Temperature Range -32 to 535°C (-25 to 999°F)Accuracy for target temperatures (assumes ambient temperature of 23°C (73°F))

Repeatability ±0.5% or ≤ ±1ºC (±2ºF), whichever is greater

Laser (Class II)

Typical Distance to TargetMAX Temp. DisplayDisplay Hold (7 seconds)LCD BacklitTripod MountingRemovable base magnetWork area illuminationAdditionalOptions/Accessories

SmartSight™ dual laser sighting systemLaser turns off above 40º C (104ºF)

ambient temperature200 mm-600 mm (8 inches to 2 feet)

✓

✓

✓

0.25” 20 UNC threading✓

Bright white LED (7100 millicandela)Nylon Holster

NIST Calibration Certificate

–32 to –26°C (-25 to -15°F): ±3ºC (±5ºF)-26 to -18°C(-15 to 0°F): ±2.5ºC (±4ºF)

-18 to 23°C (0 to 73°F): ±2ºC (±3ºF)23° to 510ºC (73º to 950ºF):

±1% of reading or ±1ºC (±2ºF), whichever is greater

Above 510ºC (950ºF): ±1.5% of reading

Distance to Spot (D:S)

0.2ºC (0.5ºF) Display Resolution

Optimized for use at 8 inchesApproximately 16:1 at focus point

Temperature Display ºC or ºF selectable


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INTRODUCTIONProduct Identification Label

Warning:Do not point lasers directly at eye or indirectly offreflective surfaces.

Cautions:All models should be protected from thefollowing:

EMF (Electro-Magnetic Fields) from enginecomponents closer than 125 mm (5inches).

Static electricity Thermal shock (caused by large or abrupt

ambient temperature changes—allow 30minutes for unit to stabilize before use)

Do not leave the unit on or near objects ofhigh temperature

FeaturesYour thermometer includes: Dual laser sighting LED Flashlight Wide temperature range MAX temperature display Back-lit graphic display Tripod mount Removable magnetic Base Durable, ergonomic construction

Options/Accessories Nylon Holster N.I.S.T./DKD Certification

DisplayA) Low battery indicator (comes on when

battery is low)B) °C/°F symbolC) Maximum temperature value (continuously

updated while the unit is on)D) Temperature displayE) Scan/Hold indicator


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F) Laser/Backlight/LED on indicatorG) Emissivity indicatorIn the scan mode, the backlit LCD displays boththe current temperature (D) and maximumtemperature (C) in Celsius or Fahrenheit (B). Theunit will hold the last reading for 7 seconds afterthe trigger is released; the word HOLD appears(E). The presence of the battery icon (A)indicates a low battery. The presence of a lightbulb (F) will indicate backlight and LED flashlightare on. When trigger is pulled triangular icon willbe present indicating laser is on.

IntroductionWe are confident you will find many uses for yourhandheld non-contact thermometer. Compact,rugged, and easy to use—just aim, pull thetrigger, and read the temperature in less than asecond. You can safely measure surfacetemperatures of hot, hazardous, or hard-to-reachobjects without contact.

How it WorksInfrared thermometers measure the surfacetemperature of an object. The unit’s optics senseemitted, reflected, and transmitted energy, whichare collected and focused onto a detector. Theunit’s electronics translate the information into atemperature reading displayed on the unit. Thelasers are used for aiming purposes only.

How to Operate the Unit

Measurement: Quick StartTo measure an object, point the unit at an object,and pull the trigger. Try to merge the 2 laser dotson your target into one dot. When using thelasers, use them only for aiming. When sightingan object, merge the 2 lasers into one foroptimum temperature reading. For more detailedoperating instructions, see “How to AccuratelyMeasure Temperature.”

Switching °C and °F; Changing theBattery; Laser/Backlight/LED On/OffBefore opening the unit’s handle to access thebattery and controls, use a Phillips headscrewdriver to remove the base magnet. To openthe unit’s handle, push the button near the triggeron the underside of the unit, and pull the handledown and forward.

To select °C or °F, slide the top switch (A) up forCelsius and down for Fahrenheit. To activate thelasers, backlight and LED flashlight, slide thelower switch (B) down. Dual lasers and LEDflashlight will turn on when the trigger is pulled.The lasers and LED flashlight will turn off whenthe trigger is released. The backlight will remainon for 7 seconds after the trigger is released.


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To change the 9V battery, attach the battery tothe battery snaps with the positive side towardthe rear of the battery compartment.

How to Accurately MeasureTemperature

Laser SightingLaser sighting consists of 2 lasers. These lasersare aimed at different angles. The point at whichthe two laser points intersect (thermometerfocused) is 8 inches (200 mm). This is also theoptimum measuring distance.

To sight object being measured, press trigger toturn on laser sight. Only one laser point shouldbe seen when at optimum measuring distance(1). If two laser points are visible (2), adjustdistance of unit from object being measured. If itis not possible to adjust the distance, seeDistance & Spot Size information.

Distance & Spot SizeThe relationship between distance and spot sizeis 16:1 at the focus point (200mm: 13mm or 8

inches: 0.5 inch). As the distance (D) from theobject decreases or increases, the spot size (S)of the area measured by the unit becomes larger.The spot sizes indicate 90%-encircled energy.

EmissivityEmissivity is a term used to describe the energy-emitting characteristics of materials. Most organicmaterials and painted or oxidized surfaces havean emissivity of 0.95 (pre-set in the unit).Inaccurate readings can result from measuringshiny or polished metal surfaces. Tocompensate, cover the surface to be measuredwith masking tape or flat black paint. Allow timefor the tape or paint to reach the sametemperature as the material underneath it.Measure the temperature of the tape or paintedsurface.

Locating a Hot or Cold SpotTo find a hot or cold spot, aim the thermometeroutside the area of interest. Then scan acrossthe area with an up and down motion until youlocate the hot or cold spot.


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LED IlluminationAn LED is located on the front of the unit. Whenthe trigger is pulled, notice a bright LEDilluminates the area including and around thearea being measured for convenience unlessswitched off.

Magnetic BaseA removable magnetic base is attached to thebottom of unit, below the handle. The magneticbase allows the unit to be attached to any ferrousmetal surface. The magnet’s surface has beenengineered not to scratch finishes by recessingthe actual magnets. However, metal shavingsand debris can be inadvertently picked up by themagnetic, and if not removed and cleaned, candamage the finish of a surface. The magneticbase is attached to the unit using a Phillips headscrew and can easily be removed using ascrewdriver.

Reminders Not recommended for use when measuring

shiny or polished metal surfaces (stainlesssteel, aluminum, etc.). See “Emissivity” formeasuring these surfaces.

The unit cannot measure throughtransparent surfaces such as glass orplastic. It will measure the surfacetemperature of these materials instead.

Steam, dust, smoke, or other particles canprevent accurate measurement byobstructing the unit’s optics.

The thermometer can be pointed using thesighting guides on top of the unit wheneverit is difficult to see the laser sightingsystem.

MaintenanceLens Cleaning: Blow off loose particles usingclean compressed air. Gently brush remainingdebris away with a soft brush. Carefully wipe thesurface with a moist cotton swab. The swab maybe moistened with water.

Note: Do not use solvents to clean the plasticlens.

Cleaning the housing: Use soap and water on adamp sponge or soft cloth.

Note: Do not submerge the unit in water.

CE CertificationThis instrument conforms to the followingstandards: EN61326-1 EMC EN61010-1 EN60825-1 Safety

Tests were conducted using a frequency range of80–1000 MHz with the instrument in threeorientations.

Note: Between 165 MHz and 880 MHz at3V/m, the instrument may not meet its statedaccuracy.


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Troubleshooting

Code Problem Action– – – (on display) Target temperature is over or

under rangeSelect target within specifications

Battery iconLow battery Check and/or replace battery

Blank display Possible dead battery Check and/or replace battery

Laser doesn’t work (1) Low or dead battery(2) Laser turned off(3) Ambient temperature above

40°C (104°F)

(1) Replace battery(2) Turn laser on(3) Use in area with lower ambient

temperature

ERR Possible damage by EMF Contact your distributor


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APPLICATIONSTABLE OF CONTENTS

A/C-HEATER SYSTEM ...................................... 7

BEARINGS, BUSHINGS, CV JOINTS &UNIVERSAL JOINTS.......................................... 8

BRAKES.............................................................. 9

COOLING SYSTEM.......................................... 11

ENGINE PERFORMANCE ............................... 13

HEATED SEATS............................................... 15

REAR WINDOW DEFROSTER........................ 16

TIRE PRESSURES & WHEEL ALIGNMENT ... 16

A/C-Heater System

A/C System – Cooling

NOTE: Before and after performing repairson the A/C refrigerant system,discharge/charge refrigerant using approvedrefrigerant recovery/recycling equipment.

When A/C is on and set at maximum cooling, airtemperature from instrument panel ducts shouldbe a minimum of 15°C (25°F) cooler thanambient temperature. To verify A/C outlettemperature, start vehicle and set A/C to coldestsetting using dash vents. Set A/C controls toMAX-A/C or re-circulate position. Test-drivevehicle if possible. If test is to be performed inservice bay, place a large fan in front of thevehicle to ensure A/C condenser has sufficientairflow for an accurate temperature reading. Ifvehicle is stationary, raise idle and allow A/Csystem to stabilize before measuring outlet

temperature. Ensure windows are rolled up anddoors are closed.

CAUTION: To avoid thermal-shock of IRthermometer, DO NOT hold unit directly in theflow of the A/C outlet when measuring A/Cduct surface temperature or measuring othercomponents near A/C ducts. Hold unit off toone side when measuring to avoid directcontact with cold airflow.

Using the IR thermometer, measure A/C outlettemperature. If outlet temperature is at 15°C(25°F) cooler than ambient temperature, A/Csystem is cooling sufficiently. If outlettemperature is less than 15°C (25°F) cooler thanambient temperature, check for the following: Restricted liquid line to evaporator (check

for ice on liquid line to evaporator). Restricted expansion valve or orifice tube

(check for ice on expansion valve or orificetube).

Measure temperature of condenser to check forcold spots. If cold spots are found, this willindicate a restriction in the condenser. Parallelflow condensers will normally have an eventemperature drop from one side to the other whileserpentine condensers will show a drop intemperature from top to bottom.If A/C compressor is cycling on and off with less“on” time than normal, check for low refrigerantcharge. If A/C compressor is not operating at all,diagnose and repair A/C system usingappropriate service information.

Automatic A/C SystemOn many vehicles with automatic A/C systems,sensors are used to determine ambient (outside)and cabin (in-car) temperatures to controlfunctions of the A/C-Heater system. Often, alongwith these sensors, the A/C system may have theability to display current ambient and in-cartemperature provided by these sensors, on theA/C controls. Most ambient temperature sensorsare mounted outside the passenger


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A/C-Heater System (Cont.)compartment, near the front of the vehicle. Mostin-car temperature sensors are mounted on theinstrument panel. See manufacturer’s informationto identify exact location of sensors, if equipped.To verify correct operation of sensors, use the IRthermometer to measure ambient temperaturenear the ambient temperature sensor and in-cartemperature near the in-car temperature sensor.Compare readings to A/C control. If themeasured and displayed temperatures are notapproximately the same, a problem with thesensor or A/C system may exist.

Heater System

WARNING: Engine coolant can reachtemperatures exceeding 125°C (260°F). Allowengine to cool before performing repairs onheater system or serious injury may occur.

Heater systems on most vehicles are connecteddirectly to the engine cooling system using theengine water pump and coolant system pressureto provide coolant to the heater core. On othervehicles a separate water pump is used tocirculate water for the heater system. A heatercontrol valve, controlled by the A/C system, isused in some applications to stop flow of coolantinto heater core to prolong heater core life and toaid in cooling the passenger compartment whenA/C is in use. When trouble shooting heatercores, ensure A/C system is off and heatercontrol valve is open as to not stop flow ofcoolant to heater core. Inspect coolant level andtop off as necessary to ensure air will not betrapped in heater core during testing.Ensure vehicle is at operating temperature,approximately 85-105°C (190-220°F). Verifyoperating temperature has been reached bymeasuring temperature at upper radiator hosenear the thermostat housing. If vehicle does notreach operating temperature, trouble shoot thecooling system first.Using the IR thermometer, measure inlet andoutlet hose temperature near firewall. Thetemperature reading of the inlet hose should beapproximately 10°C (20°F) hotter than the outlet

hose. If the outlet hose is not hot or thetemperature differential between the inlet and theoutlet hose is greater than 10°C (20°F), coolantis not flowing through the heater core. Check forthe following: Plugged/Restricted heater core. Heater control valve not opening.

Bearings, Bushings, CV Joints& Universal JointsBearings, bushings, CV joints and universal jointsall have friction surfaces that require properclearance and lubrication to operate properly.Some of these components are sealed and donot require service while some are equipped withfittings to allow regular maintenance. Followingmanufacturers recommended maintenanceintervals is key to ensuring proper operation of allfriction surfaces.

Bearings & Bushings – IncludingTrailersMost bearing and bushing problems can berelated with a growl noise or metal-on-metalcontact. Once a noise is heard, damage hasoccurred. A bearing or bushing that hasdeteriorated this far can possibly damage thecomponent it has been designed to protect. Toprevent this type of damage, whenever possible,perform a through visual inspection to check fordamaged or leaking seals. On wheel bearings,check for uneven wear of brake pads orexcessive axial movement of wheels.Bearings and bushings can be checked beforedamage occurs. To check for deteriorating wheelbearings, test-drive vehicle a short distance. Stopvehicle, place in Park (auto trans) or neutral(manual trans) and set parking brake.Using the IR thermometer, measuretemperatures at all wheel bearings and/or hubs.The bearing or hub with a higher temperature ascompared to other bearings/hubs will indicatepotential bearing failure. Verify that a brake dragis not causing the difference in temperature.Inspect components and repair as necessary.


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Bearings, Bushings, CV Joints& Universal Joints (Cont.)

NOTE: It is advised to check all wheelbearings/hubs at the same time to ensure allare in good working order.

On other items such as alternator bearings,differential pinion bearings or distributor bushingsthat do not have a like component to comparetemperature readings measure temperature ofcomponent away from bearing/bushing area.Then measure bearing/bushing area. Whenoperating properly, temperature should notchange significantly between the component andthe bearing/bushing area. If temperatureincreases at the bearing/bushing area, inspectthe bearing/bushing and repair as necessary. Oncomponents such as alternators, check for brownresidue expelling from bearings indicatingbearing deterioration.

CV Joints & Universal JointsCV joints and universal joints operate typicallythe same as bearings. Lubrication and clearanceare key to proper operation. On a CV joint, anoise or symptom is usually not heard untildamage is done. On a universal joint, often asqueak or a vibration will indicate a marginalcomponent. To prevent this type of damage,whenever possible, perform a thorough visualinspection to check for damaged/torn boots orleaking seals.To trouble shoot CV joints and universal joints,test-drive vehicle a short distance. Stop vehicle,place in Park (auto trans) or neutral (manualtrans) and set parking brake.Using the IR thermometer, measuretemperatures at all CV joints or universal joints.The CV joint or universal joint with excessivetemperature as compared to other CV/universaljoints will indicate potential bearing failure.Remove, inspect and repair as necessary.

BrakesFamiliarity with the different types of brakingsystems can aid in choosing the correct path ofdiagnosis. High temperature at one brake doesnot mean that is the brake with the problem. Ifanother brake is not operating properly, then thebrake that is hotter may be having to work harderto stop the vehicle. See appropriate service forinformation to verify type of braking system forvehicle.

NOTE: Before trouble shooting brakes,ensure all tires are properly inflated tomanufacturer’s specification. Ensure tire sizeon vehicle is the same across the front or rearand that bias-ply and radial tires are notmixed.

CAUTION: Both front or rear brakes shouldbe serviced at the same time to ensure brakesare at optimum operating condition.

Front/Rear Split Brake SystemsOn vehicles equipped with front/rear split brakesystems, each circuit of the master cylinderoperates either the front or rear brakes.See Fig 1.

Fig. 1: Front/Rear Split Brake System

The front brakes will normally have highertemperatures than rear brakes when workingproperly. Normal temperature differentialbetween front and rear brakes is 30°C (50°F).This procedure checks operation of front and rearbrakes on these systems and applies to vehicleswith disc/disc, drum/drum or disc/drum brakeconfiguration.


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Brakes (Cont.)To obtain an accurate temperature reading, testdrive vehicle in a low-traffic area, preferably on astraight, level section of roadway. Operatevehicle to 50 KM/H (30 MPH) and bring to acomplete stop 5 times. Stop vehicle, place inPark (auto trans) or neutral (manual trans) andset parking brake. Using the IR thermometer,measure temperature of front and rear brakes.See Figs. 2 & 3.

Fig. 2: Measuring Disc Brake Temperatures

If temperature differential between front and rearbrakes is greater than 30°C (50°F), rear brakesmay not be working effectively. Check thefollowing: Front brake adjustment too tight (drum

brakes - front). Rear brake adjustment too loose (drum

brakes - rear). Emergency brake adjustment. Combination valve malfunction. Master cylinder malfunction (check for loss

of brake fluid without a visible fluid leak). Leaking calipers or wheel cylinders. Master cylinder overfilled. Brake line or hose restriction.

If temperature differential is less than 30°C(50°F), or rear brake temperature is hotter thanfront brakes, front brakes may not be workingeffectively. Check the following: Front brake adjustment too loose (drum

brakes - front).

Rear brake adjustment too tight (drumbrakes - rear).

Emergency brake adjustment too tight. Combination valve malfunction. Master cylinder malfunction. Leaking calipers or wheel cylinders. Brake line or hose restriction.

Some vehicles also have a load-sensing valvenear the rear brakes. Check this valve for properoperation where applicable.

Fig. 3: Measuring Drum Brake Temperatures

Diagonal Split Brake SystemsDiagonal split brake systems differ from front/rearsplit systems in that each circuit of the mastercylinder operates one front brake and thediagonally opposite rear brake. See Fig. 4.As in front/rear split brake systems; diagonal splitbrake systems front brakes will normally havehigher temperatures than rear brakes whenworking properly. Normal temperature differentialbetween front and rear brakes is 30°C (50°F).Diagonal split brake system symptoms are oftenrelated with a brake pull. This is when the vehiclepulls to left or right when the brakes are applied.This procedure trouble shoots operation of thediagonal split brake system and applies tovehicles with disc/disc or disc/drum brakeconfiguration.To obtain an accurate temperature reading, testdrive vehicle in a low-traffic area, preferably on astraight, level section of roadway. Operate


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Brakes (Cont.)vehicle to 50 KM/H (30 MPH) and bring to acomplete stop 5 times. Stop vehicle, place inPark (auto trans) or neutral (manual trans) andset parking brake. Using the IR thermometer,measure temperature of each front and each rearbrake. See Figs. 2 & 3. If the temperaturereading of one brake on the front of the vehicle is3°C (5°F) greater than the other front brake andthe diagonally opposite brake on the rear is also3°C (5°F) greater than the other rear brake,check for the following: Master cylinder malfunction (check for loss

of brake fluid without a visible fluid leak). Master cylinder overfilled. Leaking calipers or wheel cylinders. Brake line restriction. Combination valve malfunction.

Fig. 4: Diagonal Split Brake System

Some vehicles also have a load-sensing valvenear the rear brakes. Check this valve for properoperation where applicable. If temperaturedifferential is greater than 3°C (5°F) onlybetween the two front brakes or the two rearbrakes, check for conditions associated withbrake drag at one or more brakes.

Brake Drag/Pull (Left/Right)Vehicle may pull to one side when brakes areapplied. One wheel may lock up under braking.Uneven brake pad/shoe wear or glazed surfacemay accompany condition. Heat damage torotor/drum may also exist. This procedure appliesto vehicles with disc/disc, drum/drum ordisc/drum brake configuration and also tofront/rear and diagonal split brake systems.

To obtain an accurate temperature reading, test-drive vehicle in a low-traffic area, preferably on astraight, level section of roadway. Operatevehicle to 50 KM/H (30 MPH) and bring to acomplete stop 5 times. Make sure brakesymptom is duplicated. Stop vehicle, place inPark (auto trans) or neutral (manual trans) andset parking brake. Using the IR thermometer,measure temperature of all brake rotors/drums.See Figs. 2 & 3. If temperature differential of onebrake is greater than 3°C (5°F) compared to theother brake on the same axle, check for thefollowing at all brakes: Binding caliper hardware (disc brakes). Frozen caliper (disc brakes). Leaking calipers or wheel cylinders. Broken, loose or missing brake hardware. Brake adjustment (drum brakes). Worn or damaged backing plates (drum

brakes). Wheel bearing adjustment. Leaking bearing or axle seals

(contaminated pads/shoes). Brake hose restriction.

On drum brakes, check that automatic brakeadjusters operate properly. If temperaturedifferential between brakes is small or non-existent, worn suspension components oralignment of vehicle may be causing pull.

Cooling SystemWARNING: Engine coolant can reachtemperatures exceeding 125°C (260°F). Allowengine to cool before performing repairs oncooling system or serious injury may occur.

Each vehicle has its own optimum operatingtemperature and a threshold beyond that to allowvehicle operation without causing damage toengine components. A cooling system may beoperating fine and have no visible signs oftrouble, yet for some reason the vehicle may berunning hot, have a fluctuating temperature orpossibly overheating. The task is to be able totrouble shoot and repair the cooling system


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Cooling System (Cont.)before the vehicle overheats and to preventdamage to engine.

Note: Before trouble shooting coolingsystem, ensure coolant leaks DO NOT existand cooling fans operate properly.

Radiator Trouble ShootingRadiators are hard to trouble shoot visually. Theradiator will either leak or not leak. You may beable to pull the radiator cap off and look inside atthe ends of the passages. The cap may look newand the seal good. Unless there is excessivedamage or corrosion, the radiator may not beconsidered suspect.Internally there are many passages that can beblocked or restricted, causing cool spots thatdecrease the radiators flow and effectiveness atlowering the temperature of the coolant to theengine.

CAUTION: On vehicles with mechanicalfans, use care not to place tools or hands intomoving blades to prevent injury. On vehicleswith electric fans, be cautious when workingnear because the fan may turn on at any time.

To trouble shoot for radiator blockage, startengine and run until normal operatingtemperature of 85-105°C (190-220°F) is reachedand temperature stabilizes. For vehiclesequipped with electric cooling fans, ensure fanscycle on and off three times prior to checkingtemperatures.Using the IR thermometer, measure radiatorsurface temperature. On vehicles equipped witha cross flow radiator, measure temperature frominlet side (hose from thermostat) to outlet side(hose from water pump inlet). Temperatureshould decrease evenly from inlet side to outletside. On vehicles equipped with a down flowradiator, measure temperature from top tobottom. Temperature should decrease evenlyfrom top to bottom. Also measure temperature atvarious points across radiator fins. If there is adrop in temperature at one section, this indicates

a blockage or restricted flow. Also check for bentfins restricting airflow.

Thermostat Opening TemperatureAs an engine reaches normal operatingtemperature, approximately 85-105°C (190-220°F) on most vehicles, the thermostat shouldopen and allow coolant to flow through theradiator. Using the IR thermometer, measure thetemperature of the upper radiator hose near thethermostat housing as engine reaches operatingtemperature. When the thermostat opens at thespecified temperature, the temperature of theupper radiator hose should quickly increase. Iftemperature at upper radiator hose near thethermostat housing does not increase, check forthe following: Stuck closed thermostat causing coolant

not to flow (engine temperature will behigh).

Stuck open thermostat, causing coolant toflow constantly and not increase intemperature.

Air in cooling system (possibly from notbeing properly bled).

If temperature remains low and does not reachnormal operating temperature, check for thefollowing: Stuck open thermostat, causing coolant to

flow constantly and not increase intemperature.

Missing thermostat. Thermostat with opening temperature too

low for vehicle.

If temperature of upper radiator hose fluctuatesup and down, check for the following: Weak thermostat spring. Air in cooling system (possibly from not

being properly bled).

A fluctuating temperature gauge may accompanyfluctuating temperature at upper radiator hose.


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Engine Performance

Engine Misfire Trouble Shooting –GasolineA gasoline engine may idle rough or have anintermittent misfire. Lack of fuel, lack of spark orlack of cylinder pressure (compression) cancause misfires. In a gasoline engine, any of thesethree problems means no combustion in thatcylinder. No heat coming from the exhaust portwill indicate lack of combustion. A lean fuelcondition will cause a higher combustiontemperature. Individual exhaust temperature willbe easier to obtain on vehicles equipped withseparate exhaust pipes for each port. On exhaustmanifolds, heat transfer will occur and make itdifficult to identify changes in temperaturebetween ports. The best results on a manifold willbe observed when the vehicle is first started andthe engine is cold. On newer vehicles, if acylinder is not operating effectively, the checkengine light may turn on and a DiagnosticTrouble Code (DTC) will be set.To locate a misfiring cylinder using the IRthermometer, start engine and allow the idle tostabilize. Measure temperature at each exhaustport, noting changes in temperature. See Fig. 5.If any cylinders show a significantly lowertemperature than other cylinders, check thatcylinder for the following: Malfunctioning ignition supply to affected

cylinder. Malfunctioning fuel supply to affected

cylinder (rich condition). Excessively low cylinder pressure

(compression).

If any cylinders show a significantly highertemperature than other cylinders, check for a fuelrestriction to affected cylinder causing a leanmisfire. Most likely cause is a dirty fuel injector orvacuum leak.If any cylinders indicate a noticeable, but notsignificantly lower or higher temperature thanother cylinders, this could be an indication ofpoor cylinder performance. This check may warnof other mechanical problems. Check for thefollowing:

Worn spark plugs or wires. Malfunctioning fuel supply to affected

cylinder (rich/lean condition). Low cylinder pressure (compression). Carbon buildup.

Fig. 5: Measuring Exhaust Port Temperatures

Engine Misfire Trouble Shooting –DieselA diesel engine may be hard to start, lack poweror idle rough in all climates and at all operatingtemperatures. The engine may have a cylinderthat is misfiring.To locate a misfiring cylinder using the IRthermometer, start engine and run until enginereaches normal operating temperature. Runengine at a fast idle and measure temperature ateach exhaust port, noting changes intemperature. See Fig. 5. A weak cylinder can beidentified as having a temperature less thansurrounding cylinders of 55°C (100°F) or more. Ifa weak cylinder is found, check that cylinder forthe following: Malfunctioning fuel injectors or fuel injector

pump. Excessively low cylinder pressure

(compression).

Engine Temperature SensorsEmission controls on most computer-controlledvehicles rely on many sensor inputs, allowingproper control of spark and fuel supply in allclimate and driving conditions. Engine CoolantTemperature (ECT) sensor and Intake AirTemperature (IAT) sensor (if equipped) inputscan be verified using the IR thermometer. To


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Engine Performance (Cont.)verify ECT and IAT sensor inputs, a scan tool orother data device with proper software installedwill need to be connected to the vehicle to enableviewing of the actual ECT and IAT sensortemperature readings.Start engine and run until normal operatingtemperature of 85-105°C (190-220°F) is reachedand temperature stabilizes. For vehiclesequipped with electric cooling fans, ensure fanscycle on and off three times prior to checkingtemperatures.To verify ECT sensor temperature, monitor ECTsensor temperature reading on scan tool. Onmost vehicles the ECT sensor is threaded intothe cooling system, near the thermostat.Measure temperature where ECT sensor threadsinto engine. Compare temperature readings. Iftemperature readings are not approximately thesame, check for the following before diagnosing: Damaged ECT sensor, connector or wiring. Air in cooling system (possibly from not

being properly bled).

To verify IAT sensor temperature, turn engine offand ignition on. Monitor IAT sensor temperaturereading on scan tool. On some vehicles the IATsensor may be threaded into the intake airducting before the throttle body. On othervehicles it may be threaded directly into theintake manifold after the throttle body. Afterengine reaches operating temperature, it may bedifficult to verify IAT sensor temperature whenthreaded into the intake manifold. On vehicleswhere the IAT is threaded into the intake airducting, remove ducting to access IAT sensorwithout disconnecting IAT sensor. Measure airtemperature around IAT sensor. Comparetemperature readings. If temperature readingsare not approximately the same, check for thefollowing before diagnosing: Contaminated or damaged IAT sensor,

connector or wiring. Damaged intake air ducting.

Catalytic Converter - EfficiencyAn engine may run fine yet fail an emissions test.The catalytic converter efficiency can bechecked. Start engine and test drive vehicle until

normal operating temperature of 85-105°C (190-220°F) is reached and temperature stabilizes. Onsome vehicles the catalytic convertertemperatures will lower and become insufficientfor testing purposes if the vehicle is left idling fora prolonged period of time. For vehiclesequipped with electric cooling fans, ensure fanscycle on and off three times prior to testingcatalytic converter. During test, hold throttle tokeep engine running at 1000 RPM.

Fig. 6: Measuring Converter Inlet & OutletTemperatures

Using the IR thermometer, measure the inlet andoutlet temperatures of the converter. See Fig. 6.Compare inlet temperature to outlet temperature.On vehicles equipped with 2-way catalyticconverters, temperature differential will be 55°C(100°F) or more. On vehicles equipped with 3-way catalytic converters, temperature differentialwill be 20°C (30°F) or more. The outlettemperature will be hotter when the converter isoperating properly. If temperature differentialbetween converter inlet and outlet are less thanspecified or the application, then the converterneeds to be inspected further. Before replacingthe catalytic converter, determine cause offailure. Catalytic converters are designed to lastthe life of the vehicle. If vehicle has high mileageof over 240,000 kilometers (150,000 miles) it isprobably just expired. If the vehicle has lowmileage of less 240,000 kilometers (150,000miles) then check for the following: Ignition system malfunction (misfire). Fuel system malfunction (over-lean or

over- rich condition). Emission system operation (O2, air

injection, etc).


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Engine Performance (Cont.) Engine coolant in combustion chamber

(leaking/blown head gasket). Excessive oil getting past rings or valve

guides.

Trouble shoot and repair problem and retestbefore replacing catalytic converter.

Catalytic Converter – Plugged

CAUTION: If a vehicle is operated with aplugged catalytic converter for any length oftime, possible engine damage may result.

If a catalytic converter is exposed to a roughrunning or improperly maintained engine forextended periods of time, the end result could bea plugged converter or exhaust system.Symptoms of a plugged catalytic converter will belack of power, engine temperature increasing asvehicle is driven, and if the converter has beenplugged for a while, the exhaust manifold gasketswill blow out.To check for a plugged converter, start engineand test drive until normal operating temperatureof 85-105°C (190-220°F) is reached andtemperature stabilizes. On some vehicles thecatalytic converter temperatures will lower andbecome insufficient for testing purposes if thevehicle is left idling for a prolonged period oftime. For vehicles equipped with electric coolingfans, ensure fans cycle on and off three timesprior to testing catalytic converter. During test,hold throttle to keep engine running at 1000RPM.Using the IR thermometer, measure the inlet andoutlet temperatures of the converter. Compareinlet temperature to outlet temperature. When aconverter is plugged, the converter outlettemperature will be cooler than the inlettemperature. In some cases, the catalyst insideof the converter will break apart and end upplugging the exhaust in the muffler. In this case,the inlet and outlet temperatures of the converterwill be close as with an expired converter. If thisis the case, the converter and muffler will need to

be removed, inspected and repaired asnecessary.Before replacing the catalytic converter,determine cause of failure as to not damage newconverter.

Heated SeatsSome vehicles are equipped with heated seatsas an option. Some heated seats have 2-positionLOW/HIGH heating capabilities. Vehicle mayalso be equipped with rear heated seats.On most vehicles, seat temperature will reach35°C (98°F) when in LOW position andapproximately 45°C (110°F), when in HIGHposition. Internal temperature sensors will ensureheated seats will operate at these temperaturesas closely as possible. Seat temperature mayvary by manufacturer. See appropriate serviceinformation for exact operating temperatures forvehicle being serviced.Before checking heated seat temperatures, verifyif vehicle is equipped with heated seat cushions,heated seat backs or both heated seat cushionsand seat backs. If possible, park vehicle out ofsunlight and allow cabin (in-car) temperature tostabilize.Using the IR thermometer, measure heated seatcushion and/or seat back surface with all heatedseats off. Measure other seats to get a generaltemperature reading of seat surfaces.Temperature should be close between all seats.If surface temperature is noticeably hotter,heated seat may be stuck on. Next, turn ignitionon and set heated seat switch to LOW positionand allow 5 minutes for seat temperature tostabilize. Measure heated seat cushion and/orseat back surface again. Verify that LOWtemperature reading is close to 35°C (98°F).Next, set heated seat switch to HIGH positionand allow 5 minutes for seat temperature tostabilize. Measure heated seat cushion and/orseat back surface again. Verify that HIGHtemperature reading is close 45°C (110°F). Iftemperature readings are hotter or cooler,diagnose heated seat system using appropriateservice information.


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Rear Window Defroster

Locating Broken Grid LinesRear window defroster uses heat through voltageto defrost the rear window using metal stripsattached to the inside of the rear window. Tovisually locate broken grid lines is difficult. Totrouble shoot defroster system grid lines turnignition on and activate rear window defroster.Using the IR thermometer, measure temperatureacross each defroster grid line from left to rightfrom inside of window. Temperature shouldincrease from left to right on grid line astemperature is measured. If temperature remainsconstant across grid line, check for a looseground for defroster grid. Temperature drops willindicate location of broken grid lines. See Fig. 7.If defroster does not turn on or temperature doesnot increase, problem may be in voltage supplycircuit, relay or defroster switch. See appropriateservice information to diagnose and repair.

Fig. 7: Locating Broken Grid Lines

Tire Pressures & WheelAlignment

NOTE: Before trouble shooting tirepressures or alignment, ensure all tires areproperly inflated to manufacturer’sspecification. Ensure tire size on vehicle isthe same across the front or rear and thatbias-ply and radial tires are not mixed.

Tire temperatures can tell you how well the tire isusing the tread surface and the road surface tomaintain control. The objective is to get the tire towork effectively across the entire face of the tire.This can be maximized for most vehicles byadjusting tire pressures and alignment.

Tire Temperatures/Pressures

CAUTION: Some vehicles are equipped withtire pressure monitoring systems. If airpressure is adjusted, system may set awarning light. Check manufacturer’sinformation before adjusting air pressurebeyond factory specifications.

Optimum tire temperature should be little to notemperature differential across the tire tread. Ona vehicle such as a taxi or a truck, this proceduremay not be suitable because of the varying loadsimpressed upon the tires.Tire manufacturers recommend tire temperaturedifferential for passenger car tires across thetread should be less than 10°C (20°F).Before test drive, ensure tires are properlyinflated to manufacturer’s specifications.To obtain an accurate temperature reading, testdrive vehicle in a low-traffic area, preferably on astraight, level section of roadway. Operatevehicle at a safe speed and bring to a completestop. Try to avoid any sharp turns or movementsduring test drive. Stop vehicle, place in Park(auto trans) or neutral (manual trans) and setparking brake. Using the IR thermometer,measure temperature at inside, center andoutside of tire tread surface. See Fig. 8.

Fig. 8: Measuring Tire Temperatures


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Tire Pressures & WheelAlignment (Cont.)If the center temperature is higher than the insideand outside temperatures, the tire is probablyover inflated. Try reducing pressure in 2-psi (14kPa) increments and recheck. If the middletemperature is lower than the inside and outsidetemperatures, the tire is probably under inflated.Try increasing pressure in 2-psi (14 kPa)increments and recheck.

Wheel AlignmentTemperatures can be used to determinecondition of alignment before tread wear isevident. Before attempting to trouble shoot wheelalignment using tire temperature readings,ensure tires are properly inflated tomanufacturer’s specifications. On many vehicles,front and rear suspension alignment can beadjusted. See appropriate service information toverify if vehicle is equipped with front and rearalignment adjustments.

Fig. 9: Identifying Toe

The following are alignment conditions that canbe diagnosed using tire temperatures. Toe-In - This is when the distance between

the front (1) centerline of the tires is shorterthan the distance between the rear (2)centerline of the tires. See Fig. 9.

Toe-Out - This is when the distancebetween the rear (2) centerline of the tiresis shorter than the distance between thefront (1) centerline of the tires. See Fig. 9.

Negative Camber - This is when the top ofthe tire leans in toward the vehicle (1). SeeFig. 10.

Positive Camber - This is when the top ofthe tire leans away from the vehicle (2).See Fig. 10.

Caster – Caster will not cause tire treadwear or increase tire temperatures. Castercan cause a pull.

To obtain an accurate temperature reading, testdrive vehicle in a low-traffic area, preferably on astraight, level section of roadway. Operatevehicle at a safe speed and bring to a completestop. Try to avoid any sharp turns or movementsduring test drive. Stop vehicle, place in Park(auto trans) or neutral (manual trans) and setparking brake.Using the IR thermometer, measure temperatureat inside, center and outside of tire tread surfaceon all tires. See Fig. 8.

Fig. 10: Identifying Camber (Positive CamberShown)

If tire temperatures are higher on the inside ofboth tires, check for the following: Excessive toe-out condition. Excessive negative camber at both wheels. Ride height too low (causing excessive

negative camber). Excessive play in steering or suspension

components (tie-rod ends, ball joints,bushings, etc.).


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Tire Pressures & WheelAlignment (Cont.) Bent steering or suspension components. Collapsed springs. Bent axle or axle housing (solid front/rear

axle vehicles).

If tire temperatures are hotter on the outside ofboth tires, check for the following: Excessive toe-in condition. Excessive positive camber at both wheels. Ride height too high (causing excessive

positive camber). Bent steering or suspension components. Bent axle or axle housing (solid front/rear

axle vehicles).

If tire temperature on one tire is hotter on theinside only, check for the following: Excessive amount of negative camber at

that wheel. Excessive play in steering or suspension


Bent or damaged steering or suspensioncomponents.

Collapsed spring. Bent axle or axle housing (solid front/rear

axle vehicles).

If tire temperature on one tire is hotter on theoutside only, check for the following: Excessive amount of positive camber at

that wheel. Excessive play in steering or suspension


Bent or damaged steering or suspensioncomponents.

Bent axle or axle housing (solid front/rearaxle vehicles).


Noncontact Temperature Measurement€¦ · Noncontact Temperature Measurement Manual 57560-1 Rev A...

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