General IRT3 User Manual

Please read this manual carefully and thoroughly before using this product.

4:1 MINI INFRARED

THERMOMETER

USER’S MANUAL

IRT3

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H

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INTRODUCTION

The IRT3 is a small and lightweight non-contact thermometer
that measures the surface temperature of an object from a
distance by using an IR sensor to measure its thermal
radiation. A laser pointer indicates the target area (spot)
whose temperature is being measured.

SAFETY INSTRUCTIONS

The IRT3’s targeting laser is a Class 2 type that emits less
than 1mW of power at a wavelength of 655nm. Avoid direct
eye contact with laser light radiation. U.S. law prohibits
pointing a laser beam at aircraft; doing so is punishable by
a fine of up to $10,000 and imprisonment.

WHAT’S IN THE BLISTER PACK

The IRT3 comes in a plastic blister pack with two
pre-installed batteries and this user’s manual.

PRODUCT OVERVIEW

Figure 1 shows the locations of the controls, indicators and
physical features of the IRT3.

D

E

F

A

B

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Fig. 1. The IRT3’s controls, indicators
and physical features

A. Meas. (measure) button B. MODE button
C. Wrist strap attachment bar
D. Laser pointer E. IR sensor window
F. LCD
G. Thermometer battery compartment
H. Laser battery compartment
I. Laser Identification/

Certification/Warning/
Safety Labels
(on upper back of unit)

Fig. 2.
All possible display
indicators and
their meanings

A. Low Battery icon
B. Laser Enabled icon
C. Indicates operation in Scan mode

(with Meas. button pressed and held)
D. Indicates measured value is being held
E. Celsius unit selected
F. Fahrenheit unit selected
G. Measured value

AB C D

E

F

G

SETUP INSTRUCTIONS

The IRT3 comes with two CR2032 batteries pre-installed in
separate compartments (Fig. 1, Callouts G and H).

To activate each battery:

1. Turn the IRT over and use your thumbs or a coin to turn its

battery compartment cover clockwise 30 degrees, in the
direction marked OPEN.

2. Pull and discard the tab under the pre-installed battery.

3. Replace the battery compartment cover and turn it

counterclockwise 30 degrees until it snaps shut.

Complete Setup by carefully removing the plastic film
protecting the LCD.

OPERATING INSTRUCTIONS

Point the front of the unit at a surface, press the Meas.
(measure) button, hold it for at least one second, and then
release. The temperature of the surface will be displayed
instantly on the LCD.

Note that if you press and hold the Meas. button while
targeting different surfaces (walls, windows, lights), the
display will track their different temperatures. This is called
operating in Scan mode. Also note that when you release
Meas. the reading will be held for 15 seconds and then
disappear as the IRT automatically powers off (to extend
battery life).

By default, the laser pointer turns on when the Meas. button
is pressed and turns off when the button is released. The
laser’s current state is indicated by the presence or absence
of the Laser Enabled icon (callout B of Fig. 2). To prepare to

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5

25@100

50@200

75@300

1@4

2@8

3@12

D:S=4:1

turn the laser off, press the MODE button twice. When the
Laser Enabled icon begins to flash, press the Meas. button to
turn off the laser. The laser will remain disabled until the IRT3
powers off. When the IRT is powered on again, the laser will
be re-enabled automatically.

To power off the IRT3, either press and hold the MODE
button for at least 3 seconds or let the Auto Power Off (APO)
function turn the IRT off after 15 seconds of front-panel
inactivity.

To change the temperature unit, press the MODE button
once. When the currently selected temperature unit begins
to flash, press the Meas. button to switch to or from °F
(the default unit) and °C.

MAKING ACCURATE MEASUREMENTS

The IRT3 has a distance-to-spot (D:S) ratio of 4:1. This means
that the target area (spot) whose infrared radiation
(temperature) is being measured increases in diameter by
1 inch for every 4 inches you move away from the target.
Conversely, the diameter of the target area measured
decreases by 1 inch for every 4 inches you move closer to
the target.

Fig. 3. The IRT3’s field of view

For example, when using the IRT3 to measure the
temperature of a motor with an area of 1 ft

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, the optimal
measurement distance would be 4 ft. To eliminate error, the
IRT must be moved close enough so the motor is the only
object in the target area (see Fig. 4 below).

Fig. 4. Measuring a motor’s temperature from the wrong
(top) and right (bottom) distance.

SPECIFICATIONS

Measurement Range/Resolution -22° to 482°F (-30° to 250°C)/0.1°
Measurement Accuracy ±3.6°F (2°C) or 2% of reading

(whichever is greater) above 32°F
(0°C); ±5.4°F (3°C) or 2% of reading

(whichever is greater) below 32°F
Measurement Repeatability 1% of reading or 1°C
Distance-To-Spot (D:S) Ratio 4:1
Emissivity Fixed at 0.95
Response Time 500 msec for 95% response
Display Type/Size LCD/1.0 (H) x 0.7 (W) in.

(25 x 18mm)
Laser Class/Power/Wavelength Class 2/<1mW/655nm

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Response Wavelength 8 to 14 um
Auto Power Off After 15 seconds of inactivity
Thermometer Battery Life 50 hours, typical
Current Consumption <40mA with laser on;

<30mA with laser off

Operating Temperature 32° to 104°F

(0° to 40°C)@<75% R.H.

Storage Temperature -4° to 140°F

(-20° to 60°C)@<85% R.H.

Dimensions 4.17 x 2.20 x 0.90 in.

(106 x 56 x 23mm)
Weight (including batteries) 2.2 oz. (62.4g)
Power Source Two CR2032 (3V) non-rechargeable

Lithium-ion cells

WARRANTY INFORMATION

In the U.S., General instruments and accessories are
warranted against defects in material or workmanship for one
year from date of purchase. General will replace or repair the
defective unit, at its option, subject to verification of the
defect.

This warranty does not apply to defects resulting from abuse,
neglect, accident, unauthorized repair, alteration, or
unreasonable use of the product.

Any implied warranties arising from the sale of a General
product, including but not limited to implied warranties of
merchantability and fitness for a particular purpose, are
limited to the above. General shall not be liable for loss of use
of the product or other incidental or consequential damages,
expenses, or economic loss, or for any claim of such damage,
expenses, or economic loss.

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State laws vary. The above limitations or exclusions may not
apply to you.

We encourage our customers to register for warranty online.
General will extend your warranty an additional 60 days if you
register at www.generaltools.com/ProductRegistry.

RETURN FOR REPAIR POLICY

Every effort has been made to provide you with a reliable
product of superior quality. However, in the event your
instrument requires repair, please contact our Customer
Service to obtain an RGA (Return Goods Authorization)
number before forwarding the unit via prepaid freight to the
attention of our Service Center at this address:

General Tools & Instruments

75 Seaview Drive Secaucus, NJ 07094 212-431-6100

Remember to include a copy of your proof of purchase, your
return address, and your phone number and/or e-mail
address.

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GENERAL TOOLS & INSTRUMENTS

75 Seaview Drive Secaucus, NJ 07094-1806

PHONE [phone] FAX [phone] TOLL FREE [phone]

e-mail: [e-mail]

www.generaltools.com

IRT3 User’s Manual

Specifications subject to change without notice

©2015 GENERAL TOOLS & INSTRUMENTS

NOTICE - WE ARE NOT RESPONSIBLE FOR TYPOGRAPHICAL ERRORS.

MAN# IRT3

05/22/15

General Tools & Instruments

GeneralToolsNYC