TENMA 72-820 operating Manual

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72-820

Infrared

Thermometer

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Model 72-820

OPERATING MANUAL

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Model 72-820: OPERATING MANUAL

Table of Contents

Title Page

Introduction Safety Information Features Display Buttons and Connector How the Thermometer works. Operating the Thermometer

Locating a Hot or Cold Spot Distance and Spot Size Field of View Emissivity Trigger Lock Switching oC/ oF HOLD

Typical Measurements

Testing Contactors (Starters) Testing Enclosed Relays Testing Fuses and Buss Connections Testing Electrical Connections

5 5 7 7 9 10 10 10 11 11 12 15 15 15 15 16 16 16 17

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Model 72-820: OPERATING MANUAL

Table of Contents

Title Page

Scanning Walls for Air Leaks or Insulation Deficiencies Testing Bearings Testing Belts and Sheaves Checking Hydronic Radiant Heat Applications Measuring Grille, Register, or Diffuser Discharge Temperature Checking for Blockage in Air-To-Air Evaporators or

Condensers Maintenance

Changing the Battery Cleaning the Lens Cleaning the Housing

Troubleshooting CE Certification Specifications

Infrared

Laser

Electrical

Physical

Environmental

17 18 19 20

21 21 21 21 21 22 22 23 23 24 24 24 24

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Model 72-820: OPERATING MANUAL

Table Title Page

1. Symbols

2. Buttons and Connector

3. Surface Emissivity

4. Troubleshooting

List of Tables

6 9 13 22

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Model 72-820: OPERATING MANUAL

List of Figures

Figure Title Page

1 Symbols and Safety Markings 2 Infrared Thermometer 3 Thermometer Display 4 Buttons and Connector 5 Locating Hot or Cold Spot 6 Distance and Spot Size 7 Field of View

7 7 8 9 10 11 11

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Model 72-820: OPERATING MANUAL

Introduction

The Model 72-820 Infrared Thermometer (hereafter, the “Thermometer”) can determine the surface temperature by measuring the amount of infrared energy radiated by the target’s surface. They have different distance to spot (D:S) figure and different temperature range, details see the contents.It features a temperature range of 0oF~1000oF and a distance-to-spot ratio of 12:1.

The non-contact infrared thermometer features low power consumption design, allowing extended use without the need to replace batteries. The highly intuitive design allows fast easy temperature measurement for increased efficiency in use.

The Thermometer may also be powered from a standard computer USB port. This can prove very convenient in situations were repeated battery changes are not practical. The Thermometer will automatically select between battery and USB port power.

Safety Information

Warning

A warning identifies conditions and actions that pose hazards to the user. To avoid electrical shock or personal injury, follow these guidelines:

Do not point laser directly at eye or indirectly

off reflective surfaces.

Before using the Thermometer inspect the case. Do not use the Thermometer if it appears damaged. Look for cracks or missing plastic.

Replace the battery as soon as the battery indicator appears.

Do not use the Thermometer if it operates abnormally. Protection may be impaired. When in doubt, have the Thermometer serviced.

Do not operate the Thermometer around explosive gas, vapor, or dust.

To avoid a burn hazard, remember that highly reflective objects will often result in lower

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Model 72-820: OPERATING MANUAL

than actual temperature measurements. Do not use in a manner not specified by this

manual or the protection supplied by the equipment may be impaired.

Caution

To avoid damaging the thermometer or the equipment under test protect them from the following:

EMF (electro-magnetic fields) from arc

welders, induction heaters, etc. Static electricity.

Thermal shock (caused by large or abrupt

ambient temperature changes – all 30 minutes from the Thermometer to stabilize before use). Do not leave the Thermometer on or near

objects of high temperature.

Table 1 and Figure 1 show various symbols and safety markings that are on the Thermometer and in this manual.

Table 1. Symbols

Symbol

Explanation

Risk of danger. Important information. See Manual. Warning. Laser Conforms to Standards of European Union Low battery.

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Model 72-820: OPERATING MANUAL

Celsius and Fahrenheit Temperature Measurement

Tripod mount

Included 9V Battery

Thermometer features are shown in Figure 2.

Figure 1. Symbols and Safety Markings

Features

The Thermometer includes:

Single-spot Laser Sighting

Intelligent USB power source

Backlit Display

Two level white colour Backlit Display (when using USB power up, this feature will be on automatically).

Current Temperature Plus MIN, MAX, DIF, AVG Temperature Displays/

Easy Emissivity Selector

Trigger Lock

Laser

Trigger

Battery Cover

Figure 2. Infrared Thermometer

Display

9V 6F22 Battery

Display

The primary temperature display reports the current or last IR temperature read until the 8-second hold time elapses.

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The secondary temperature display reports a choice of maximum, minimum, difference between maximum and minimum temperature or average value.

Model 72-820: OPERATING MANUAL

You can toggle through the maximum, minimum, difference and average IR temperatures anytime the display is on. The MAX, MIN, DIF and AV temperatures are constantly calculated and updated when the trigger is pressed. After the trigger is released, the MAX, MIN, DIF and AV temperatures are held for 8 seconds.

Laser “On” Symbol

HOLD SCAN

SCAN or HOLD

oC/o

F Symbol (Celsius/Fahrenheit)

Primary temperature Display Secondary temperature Display

Emissivity LO, MED, HI

Temperature values for the MAX, MIN, DIF,

AVG Low Battery symbol. Appears when the battery charge is <4.5V.

Figure 3. Thermometer Display

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Model 72-820: OPERATING MANUAL

Buttons and Connector

Figure 4. Buttons and Connector

Button / Connector

MODE

SET

USB port

Table 2. Buttons and Connector

Description

Press MODE button to toggle between MAX, MIN, DIF, and AVG options. Press MODE to turn the Thermometer on again and displays the last measurement result. Press to enter set up mode stepping through Emissivity set up, Trigger Lock and Switching

oC/o

F set up.

Details refer to the below Emissivity, Trigger Lock and Switching oC/oF topics. Press

to turn the display backlight on and off.

icon will be on and off also. When the Thermometer enters the setup up mode, press to select an option, details refer to the

below Emissivity, Trigger Lock and Switching oC/

F topics. Press is on,

to turn the laser on and off. After laser

will be shown. When the Thermometer enters the user setup mode, press to select an option, details refer to the below Emissivity, Trigger Lock and Switching

C/ oF topics. After connecting the USB cable, the Thermometer automatically selects USB power supply and two levels white colour Backlit Display will be on.

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How the Thermometer Works

Infrared thermometers measure the surface temperature of an opaque object. The Thermometer’s optics sense infrared energy, which is collected and focused onto a detector. The Thermometer’s electronics then translate the information into a displayed temperature reading which appears on the display. The laser is used for aiming purposes only.

Operating the Thermometer

The Thermometer turns on when you press the trigger. The Thermometer turns off when no activity is detected for 8 seconds.

To measure temperature, aim the Thermometer at the target, pull and hold the trigger. Release the trigger to hold a temperature reading.

Be sure to consider distance-to-spot size ratio and filed of view. The laser is used for aiming only.

Model 72-820: OPERATING MANUAL

To find a hot or cold spot, aim the Thermometer outside the target area. Then, slowly scan across the area with an up and down motion until you located the hot or cold spot. See Figure 5.

Figure 5. Locating Hot or Cold Spot

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Model 72-820: OPERATING MANUAL

As the distance (D) from the target being measured increases, the spot size (S) of the area measured by the unit becomes larger. The spot size indicates 90% encircled energy. The maximum D:S is obtained when the Thermometer is 600mm (23.6 in) form the target resulting in a spot size of 20mm (0.79 in). See Figure 6.

Figure 6. Distance and Spot Size

Make sure that the target is larger than the spot size. The smaller the target, the closer you should be to it. See Figure 7.

Figure 7. Field of View

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Emissivity describes the energy-emitting characteristics of materials. Most organic materials and painted or oxidized surfaces have an emissivity of about 0.95.

If possible, to compensate for inaccurate readings that may result from measuring shiny metal surfaces, cover the surface to be measured with masking tape or flat black paint (<150 oC / 302 oF) and use the high emissivity setting. Allow time for the tape or paint to reach the same temperatures as the surface beneath it. Measure the temperature of the tape or painted surface.

If you cannot use paint or use tape, then you could improve the accuracy of your measurements with the emissivity selector. Even with emissivity selector, it can be difficult to get a completely accurate infrared measurement of a target with a shiny or metallic surface.

The Thermometer allows you to adjust the unit’s emissivity for the type of surface before measured. Refer to Table 2. But it is only a typical case. You could

Model 72-820: OPERATING MANUAL

base on your own case and materials to have different setting.

To adjust values for emissivity, follow the below procedure:

Press SET to select emissivity set up, icon E on the display is blinking. The Thermometer steps through emissivity set up, trigger lock and switching oC / oF.

Press to increase the value by 0.01 or press and hold to access quick setting. The maximum value is 1.00.

Press to decrease the value by 0.0 or press and hold to access quick setting. The minimum value is 0.10.

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Model 72-820: OPERATING MANUAL

Table 3. Surface Emissivity

Measure Surface METALS Aluminum

Oxidized Alloy A3003 Oxidized Roughened

Brass

Burnished Oxidized

Copper

Oxidized Electrical Terminal Blocks

Haynes

Alloy

Inconel

Oxidized Sandblasted Electoropolished

Switch Setting

0.2-0.4

0.3

0.1-0.3

0.3

0.5

0.4-0.8

0.6

0.3-0.8

0.7-0.95

0.3-0.6

0.15

Measure Surface

Iron Cast

Oxidized Unoxidized Molten

Iron Wrought

Dull

Lead

Rough Oxidized

Molydbenum

Oxidized

Nickel

Oxidized

Platinum

Black

Steel

Cold-Rolled

Switch Setting

0.6-0.95

0.2

0.2-0.3

0.9

0.4

0.2-0.6

0.2-0.5

0.9

0.7-0.9

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Table 3. Surface Emissivity

Model 72-820: OPERATING MANUAL

Measure Surface Iron

Oxidized Rusted

NON-METALS Asbestos Asphalt Basalt Carbon

Unoxidized

Graphite Carborundum Ceramic Clay Concrete Cloth

Switch Setting

0.5-0.9

0.5-0.7

0.95

0.7

0.8-0.9

0.7-0.8

0.9

0.95

Measure Surface

Ground Sheet Polished Sheet

Zinc

Oxidized

Glass

Plate

Gravel Gypsum Ice Limestone Paper (any colour) Plastic

Opaque

Soil Water Wood, (natural)

Switch Setting

0.4-0.6

0.1

0.85

0.95

0.8-0.95

0.98

0.95

0.9-0.98

0.93

0.9-0.95

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Model 72-820: OPERATING MANUAL

To lock or unlock the trigger, use the following procedures:

1. Press SET to select trigger lock setting, the will blink.

2. Press to select ON or OFF. When the trigger is locked, the Thermometer will provide

continuous measurement. There is no need to pull the trigger.

When the trigger is unlocked, the user must pull the trigger for measurement. When the trigger is released, the Thermometer will hold the measurement result automatically.

1. Press SET to choose oC / oF selection mode,

2. Press to select oC or oF.

The display will remain activated 8 seconds after the trigger is released. HOLD appears in the upper middle of the display. When the trigger is pulled again, the Thermometer will begin measuring in the last function selected.

Typical Measurements

This section describes a variety of measurements often performed by technicians.

User could select to turn on or off the backlight and

laser whenever you are making readings with the Thermometer. But if you are using USB to power up the Thermometer, the two levels white colour backlight will be on automatically. Relatively high emissivity normally means emissivity

setting of about 0.95. Relatively low emissivity normally means emissivity

setting of about 0.30. When the emissivity of an object is unknown,

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the user may cover the surface (temperature >150oC) with black electric tape (emissivity of about 0.95). Allow time for the tape to reach the same temperature as the object to be measured. Measure and record the temperature of the tape. Target the Thermometer to the object to be measured, adjust the emissivity setting to make it as the same temperature as the tape. At this time, the Thermometer emissivity setting is close to the emissivity of the object to be measured, measurement could be started.

Press SET to select emissivity. Press / to select relatively low emissivity for bright contacts, or 0.7 mid level for darkened contacts.

Press MODE to select MAX.

Measure line and load side of one pole without releasing trigger.

A temperature difference between the line and load sides of a pole indicate increased resistance of one point and a contactor may be failing.

Model 72-820: OPERATING MANUAL

Press SET and then press / to set emissivity to relatively low for uninsulated connectors or relatively high for plastic encased relays or for bakelite enclosed relays or insulated connectors.

Press MODE to select MAX.

Start to scan.

Measure the relay casing, looking for hot spots.

Measure electrical connections on relay terminals looking for hot spots.

Press SET and then press / to set emissivity to relatively high for paper covered fuse body or insulated connections.

Press MODE to select MAX.

Scan the paper covered length of fuse.

Without releasing the trigger, scan each fuse. Unequal temperatures between fuses may indicate voltage or amperage imbalance.

Press SET and then press / to set emissivity to relatively low, for metal fuses and caps and insulated

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buss connections.

Press MODE to select MAX.

Scan each end cap on each fuse/

Press SET and then press / to set emissivity to

1. relatively low for uninsulated connectors or buss connections or relatively high for insulated connections.

Scan the conductor, moving toward direction of

2. electrical connector (quick connect, wire nut, buss connection, or lug).

Turn off heating, cooling, and blower.

1. Press SET to select emissivity. Press / to select

2. emissivity relatively high for painted surfaces or window surfaces. Press MODE to select MIN when opposite side of

3. wall is at lower temperature and or select MAX when opposite side of wall is at higher temperature. Measure an interior partition wall surface temperature.

4. Do not release the trigger. Record this temperature as your baseline (or benchmark) for a “perfectly” insulated wall. Face the wall to be scanned. Stand 1.5m away to

5. scan a 5cm spot on the wall. Scan horizontal rows of wall from top to bottom, or

6. horizontal rows of ceiling from wall to wall. Look for greatest deviations from baseline temperature to identify problems. This completes the insulation test scan.

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Turn on the blower (no heat, no cooling) and retest. If test results with the blower on are different than results with the blower off, this may indicate air leaks in conditioned envelope walls. The air leaks are caused by duct leaks that create a pressure differential across the conditioned space envelope.

Warning

To avoid injury when testing bearings:

Do not wear loose clothing, jewelry, or anything

around neck when working around moving parts such as motors, belts, blower, and fans. Make sure an electrical disconnect is within

reach and operating correctly and freely. Do not work alone.

Model 72-820: OPERATING MANUAL

Press SET and then press / to select relatively

1. high emissivity. Press MODE to select MAX.

2. Enable motor and allow it to reach steady state

3. operating temperatures. Disable the motor if possible.

4. Measure the two motor bearing temperatures

5. Compare the two motor bearing temperatures.

6. Unequal temperatures or a high temperature can indicate a lubrication or other bearing problem that is resulting from excess friction. Repeat the sequence for the blower bearings.

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Model 72-820: OPERATING MANUAL

Press SET and then press / to select relatively

1. high emissivity. Press MODE to select MAX.

2. Enable the motor and allow it to reach a steady

3. state operating temperatures. Aim the Thermometer at the surface to be measured.

4. Start recording temperature

5. Slowly move the Thermometer up the belt toward

6. second sheave.

If belt is slipping, sheave temperature will be

high from friction. If belt is slipping, belt temperature will remain

high between sheaves. If belt is not slipping, belt temperature will reduce

between sheaves. If inner surfaces of sheaves are not a true “V”

shape, this indicates belt slippage and will continue to operate at elevated temperatures until sheave is replaced. Sheaves must be properly aligned (include “pitch

& yaw”) for belt and sheaves to operate at appropriate temperatures. A straight edge or taut string, can be used to check alignments. Motor sheave should operate at a temperature

consistent with blower sheaves. If motor sheave is at a higher temperature at motor

shaft than at outer circumference, belt is probably not slipping. If outer circumference of sheave is at higher

temperature than sheave at motor shaft, then belt is probably slipping and sheaves may be misaligned.

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Radiant heat tubes in the floor will normally run parallel to the outside walls. Starting at the floor wall juncture, scan parallel to the wall while moving into the room away from the wall. Parallel to the outside wall you should find parallel isothermal rows indicating the location of heat tubes below the surface. Perpendicular to the outside wall, you should find rising and falling temperatures at equal distances. High temperatures indicate you are scanning a heat tube beneath the floor surface, low falling temperatures indicate a space between the heat tubes.

Press SET and then press / to select relatively high emissivity.

Press MODE to select MAX.

To locate radiant heat tubes in floor, temporarily elevate the loop temperature to create hotter spots for identifying tubing runs.

Before releasing trigger, press MODE to toggle between MIN, MAX, DIF floor temperatures and record the temperature for future comparison and trending under similar conditions.

Model 72-820: OPERATING MANUAL

Press SET and then press / to select relatively high emissivity.

Aim the Thermometer at the discharge air grille, register, or diffuser.

Measure discharge temperature.

Release trigger to freeze the temperature reading for 8 seconds and record this temperature.

Grille, register, or diffuser temperature should be equivalent to discharge temperature at the air handler.

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Model 72-820: OPERATING MANUAL

Maintenance

Remove panels to gain access to coil return bends or hairpins.

Press SET and then press / to select relatively high emissivity for copper tube.

Start the refrigeration system.

Aim the Thermometer at coil turn bends/hairpins.

Start recording temperature.

Take temperature of each return bend/hairpin.

All evaporator return bends/hairpins should be

at or slightly above evaporator saturation temperature from the pressure/temperature chart. All condenser return bend/hairpins should be

at or slightly less than condenser saturation temperature. If a group of return bends/hairpins do not conform

to expected temperatures, that indicates a blocked or restricted distributor or distributor tube.

To install or change the 9V battery, open the battery compartment the battery as shown in Figure 2.

Blow off loose particles using clean compressed air. Carefully wipe the surface with a moist cotton swab. The swab may be moistened with water.

Use soap and water on a damp sponge or soft cloth.

Caution

To avoid damaging the Thermometer, do NOT submerge it in water.

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Troubleshooting

Model 72-820: OPERATING MANUAL

Table 4. Troubleshooting

Symptom

OL (on display)

-OL (on display)

Blank Display Laser does not work

Problem

Target temperature is over range Target temperature is under range Low Battery Possible dead battery

1. Low or dead battery

2. Ambient temperature above 40oC (104oF)

Action

Select target with specifications Select target with specifications Replace Battery Check and / or replace battery

1. Replace battery

2. Use in area with lower ambient temperature.

CE Certification

The Thermometer conforms to the following standards:

l EN61326-1 EMC l EN60825-1 Safety

Certification testing was conducted using a frequency range of 80 to 100MHz with instrument in three orientations.

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Model 72-820: OPERATING MANUAL

Specifications

Measurement Range--------------------------------------------------------18oC to 550oC (0oF to 1022oF) Spectral Range -------------------------------------------------------------- 8 to 14 microns Accuracy ---------------------------------------------------------------------- 1.8% or (1.8oC/4oF) Temperature than less 0oC , Accuracy add to 1oC(2oF)

(Assumes ambient operating temperature of 23 to 25oC (73 to 77oF)) Repeatability ----------------------------------------------------------------- 0.5% of reading or 1oC/2oF Response Time (95%) ----------------------------------------------------- 250ms Distance to Spot (D:S) ----------------------------------------------------- 12:1 Emissivty Adjustment ------------------------------------------------------ 0.10~1.00 Display Resulation ---------------------------------------------------------- 0.1oC (0.1oF) Secondary Display Information ------------------------------------------ Maximum, Minimum, Differential, Average

Sighting --------------------------------------------------------------------------- Single point laser Power --------------------------------------------------------------------------------- Class 2 (II) operation; Output <1mV , wavelength 630 to 670mm

Power Supply -------------------------------------------------------------------- 6F22 9V Battery Power Consumption ------------------------------------------------------------ At least 30 hours battery life (Alkarine), At least 10 hours battery life (General Purpose)

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Model 72-820: OPERATING MANUAL

Weight ----------------------------------------------------------------------------- 0.322kg Size ---------------------------------------------------------------------------------17.69cm (H) x 16.36 cm (L) x 5.18cm (W)

Operating Temperature Range ---------------------------------------------- 0oC to 50oC (32oF to 120oF) Relative Humidity ----------------------------------------------------------------0 to 75% noncondensing Storage Temperature ---------------------------------------------------------- -20oC to 65oC (-4oF to 150oF)

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Model 72-820: OPERATING MANUAL

** END **

This operating manual is subject to change without notice.

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405 S. Pioneer Blvd. Springboro,Ohio 45066 www.tenma.com

Model 72-820: OPERATING MANUAL