General IRT105 User manual

6:1 POCKET INFRARED
THERMOMETER
USER’S MANUAL
IRT105
Please read this manual carefully and thoroughly before using this product.

TABLE OF CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Safety Instructions . . . . . . . . . . . . . . . . . . . . . . 4
What’s in the Blister Pack . . . . . . . . . . . . . . . . 5
Product Overview . . . . . . . . . . . . . . . . . . . . 5 –6
Setup Instructions . . . . . . . . . . . . . . . . . . . 6 –7
Install Two Batteries . . . . . . . . . . . . . . . . 6 –7
Operating Instructions . . . . . . . . . . . . . . . 7 – 16
aking Basic easurements . . . . . . . . . 7 –8
Advanced easurement odes
and Functions . . . . . . . . . . . . . . . . . . . . 8 – 11
Accounting for Emissivity . . . . . . . . . .11 – 13
aking Accurate easurements . . . . 14 – 16
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 17
Warranty Information . . . . . . . . . . . . . . . . . . . 18
Return for Repair Policy . . . . . . . . . . . . . . . . 19
anual del Usuario . . . . . . . . . . . . . . . . 20 – 39
anuel de L'Utilisateur . . . . . . . . . . . . . 40 – 59
2

INTRODUCTION
Thank you for purchasing General Tools & Instruments’
IRT105 6:1 Pocket Infrared Thermometer. Please read this
user’s manual carefully and thoroughly before using the
instrument.
The IRT105 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 defines the target area
(spot) whose temperature is being measured.
The thermometer has a wide measurement range of
-22° to 482°F (-30° to 250° ) and a distance-to-spot ratio
of 6:1. These two specifications—as well as its adjustable
emissivity and its high basic measurement accuracy
(±3°F above 32°F) —make the IRT105 ideally suited for
applications in food processing, electrical troubleshooting,
and automotive and HVA equipment maintenance. In
applications such as these, an infrared thermometer is the
only instrument capable of taking the temperature of a
surface that may be impossible to reach or too hot or cold to
touch.
The IRT105 comes in a blister pack with two non-
rechargeable R2032 Lithium-ion batteries to power its
thermometer and laser pointer.
3

KEY FEATURES
• Optimized measurement range
• Basic accuracy of ±3°F
• Adjustable emissivity
• Fast response time
• Min and Max measurement modes + Measurement
Lock mode
• Selectable °F or ° unit
• Large L D
• Separate batteries for thermometer and laser
• Auto power off
• Small and light and easy to use
SAFETY INSTRUCTIONS
CAUTI N: Use of controls or adjustments or performance of
procedures other than those specified herein may result in
dangerous radiation exposure.
The IRT105’s targeting laser is a lass 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.
4

WHAT’S IN THE BLISTER PACK
The IRT105 comes in a plastic blister pack with two R2032
batteries, a wrist strap and this user’s manual.
PRODUCT OVERVIEW
Figure 1 shows the locations of the controls, indicators and
physical features of the IRT105.
Fig. 1. The IRT105’s controls, indicators
and physical features
A. Meas. (measure) button B. Mode button
. Wrist strap attachment bar
D. Laser pointer E. IR sensor window
F. Liquid-crystal display
G. Thermometer battery compartment
H. Laser battery compartment
I. Laser Laser Identification/
ertification/Warning/
Safety Labels (on left side)
5
G
H
I
C

Figure 2 shows the icons and text that may appear on the
display. Familiarize yourself with the locations of these
controls and the meanings of these icons before moving on to
the setup and operating instructions.
Fig. 2.
All possible display
indicators and
their meanings
A. Low Battery icon
B. Laser Enabled icon
. Displaying highest measurement
D. Displaying lowest measurement
E. Operating in emissivity selection mode
F. Operating in measurement lock mode
G. elsius unit selected
H. Fahrenheit unit selected
I. Measured value
SETUP INSTRUCTIONS
INSTALL TWO BATTERIES
Two R2032 batteries (included) must be installed in separate
compartments in the back of the IRT105 (callouts G and H of
Fig. 1) to activate its thermometer and laser pointer. To open
either compartment, place the tips of your thumb and index
finger against the bumps on the round compartment cover
and turn clockwise. Insert each battery so the writing
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stenciled on it faces you. Then replace both covers and
secure them by turning them counterclockwise.
When replacing a battery, you may need to slide the tip of a
pin under it to dislodge it. Each compartment is equipped
with a pin slot (at the four o’clock) position for that purpose.
OPERATING INSTRUCTIONS
MAKING BASIC MEASUREMENTS
To make a quick measurement with the IRT105, 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
button. The temperature of the surface will be displayed
instantly on the L D in elsius or Fahrenheit units. Note that
when you release the Meas. (measure) button 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.
(measure) button is pressed and turns off when the button is
released. The laser’s default state is indicated by the
presence or absence of the Laser Enabled icon (callout B of
Fig. 2).
To change the laser’s default state from on to off, first
power off the IRT by pressing and holding the Mode button.
Then power on the unit in a special way by pressing and
holding the Mode and Meas. buttons at the same time. Note
that after doing this the Laser Enabled icon will no longer
appear on the top line of the display.
To return the laser’s default state to on, simply press and
hold the Meas. button as you would to make a quick
measurement. Note that after doing so the Laser Enabled icon
will reappear on the top line of the display.
7

To temperature-scan the surfaces of a room or any
environment, press the Meas. (measure) button and keep
pressing it as you point the IRT in various directions. Note that
the display tracks the different temperatures of different
surfaces in real time.
To power off the IRT105, either press and hold the Mode
button or let the auto power off function turn the IRT off after
15 seconds of inactivity.
ADVANCED MEASUREMENT MODES
AND FUNCTIONS
The Mode button below the Meas. button is the gateway to
the IRT105’s five advanced measurement and selection
modes (see Figure 3).
Fig. 3. The Mode button provides access to the IRT105’s five
advanced measurement and selection modes
8
Press 1x to
e ter MAX
Measureme t
mode
Press 2x to
e ter MIN
Measureme t
mode
Press 3x to
e ter
Measureme t
Lock mode
Press 4x to
e ter °C/°F
Selectio
mode
Press 5x
to e ter
Emissivity
Selectio
mode

1. MAX Measurement mode—To identify the hottest surface in
an environment, press the Meas. button to power on the IRT.
Then (within 15 seconds) press the Mode button once. This
will cause the text MAX to appear blinking on the top line of
the display. Then press the Meas. (measure) button. This
changes MAX from blinking to constant, indicating operation
in MAX Measurement mode.
Within 15 seconds, press and hold the Meas. (measure)
button and begin to scan surfaces within sight. Note that in
MAX mode the display no longer tracks the temperatures of
scanned surfaces in real time. Instead, it shows the highest
temperature measured since the Meas. (measure) button was
pressed. Also note that the maximum temperature is held
only for 15 seconds after the Meas. (measure) button is
released, causing the IRT to begin counting down to auto
power off.
To exit MAX mode and return to real-time temperature
scanning, press the Mode button. If the IRT auto powers off
while in MAX mode, it will not resume operation in MAX mode
when powered on again. It will resume operation in real-time
measurement mode.
2. MIN Measurement mode—The flip side of MAX mode, MIN
mode is entered by powering on the IRT105 and pressing the
Meas. (measure) button twice. This causes the text MIN to
appear blinking on the top line of the display. Pressing the
Meas. button changes MIN from blinking to constant,
indicating operation in MIN Measurement mode.
In MIN mode, the display shows the lowest temperature
measured so far during a scanning session. Like MAX values,
MIN values are held for only 15 seconds. To exit MIN mode
and return to real-time scanning, press the Mode button.
9

3. Measurement Lock mode—Pressing the Mode button three
times with the IRT powered on causes the word L CK to
appear blinking on the top line of the display. Pressing the
Meas. (measure) button changes L CK from blinking to
constant, indicating operation in Measurement Lock mode.
In this mode, you need not hold the Meas. (measure) button
while scanning. Surface temperatures are measured and
displayed in real time, and the IRT’s 15-second auto power off
function is disabled. Although Lock mode makes scanning
easier, it has a potential downside: the disabling of auto power
off. If you forget to exit Lock mode and then leave the IRT105
powered on for a long time, you run the risk of discharging the
thermometer battery. So remember to exit Lock mode after
using it by pressing the Mode button.
Before entering Measurement Lock mode, you should disable
the laser pointer—by powering off the IRT and then powering
it back on in a special way by pressing and holding the Meas.
and Mode buttons at the same time, as explained earlier.
Doing so will prevent accident discharging of the laser’s
battery in Lock mode over time with the auto power off
function disabled. Disabling the pointer is also a safety
precaution. If you were to leave the IRT unattended with the
laser on after putting it into Lock mode, a curious child could
enter the room and stare directly at the pointer to investigate
the source of the unusual light.
4. °C/°F Selection mode—Pressing the Mode button
four times with the IRT powered on causes the symbol of the
current default temperature unit (°C or °F) on the right side of
the display to change from constant to blinking. Pressing the
Meas. (measure) button while the term is blinking switches
all displayed readings to the other unit until the default unit is
changed again.
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5. Emissivity Selection mode—Pressing the Mode button five
times with the IRT powered on causes the Greek letter ␧to
appear blinking on the top line of the display. Unlike in other
modes, the blinking icon indicates that a new mode has already
been entered—in this case, Emissivity Selection mode.
The factory-set default emissivity value of the IRT105 is 0.95.
To enter the emissivity value of your target surface material:
• Locate the material in Table 1 in the shaded box,
Accounting for Emissivity.
• Press the Meas. button as many times as necessary to
change the display from the factory-set default value of
0.95 to the desired value. Note that each press of the
button increases the displayed value by 0.01. After five
presses, starting at 0.95, the displayed value will be 1.00.
The next press will change the value to 0.10—the lowest
possible emissivity setting. Each subsequent press of the
Meas. button will increase the value by 0.01 units.
• When you have reached the desired emissivity value, press
the Mode button to store the setting. The IRT105 will use
this value in its temperature calculations until the instrument
is powered off manually or automatically. Upon restart, the
emissivity value will return to the factory default of 0.95.
ACCOUNTING FOR EMISSIVITY
Emissivity is the ability of an object to reflect or absorb
IR radiation (energy). Because the IRT105 measures the
amount of infrared energy emitted by a surface, the IRT’s
measurements are most accurate when they take into
account the characteristic emissivity of the target material.
A perfectly absorbent surface (called a black body) has an
emissivity (represented by the Greek letter
␧ ) of 1; it
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absorbs 100% of the thermal energy hitting it. An object with
an emissivity of 0.8 absorbs 80% of IR energy and reflects
20% of it. All emissivity values fall between 0 and 1; as a
rule, the shinier the surface, the lower its emissivity. The
default emissivity setting of the IRT105 is 0.95.
To maximize the accuracy of IRT105 measurements, you
should enter the actual emissivity of the target surface via the
front panel buttons and display, as explained on pp. 10 and
11. To do so, first determine the emissivity of the surface
whose temperature you wish to measure from Table 1.
Note from the double entries for aluminum, copper, steel and
asbestos paper in the table that emissivity is only slightly
dependent on temperature. onsequently, you can confidently
use the table’s emissivity numbers for your target material
even if it is at a different temperature than specified.
ompensating for emissivity will particularly improve the
accuracy of measurements of surfaces with emissivities
nearer to zero than to the default IRT105 setting of 0.95.
Table 1. Emissivities of common materials
Material Temperature (°F/° ) Emissivity
Gold (pure, highly polished) 440/227 0.02
Aluminum foil 81/27 0.04
Aluminum disc 81/27 0.18
Aluminum (household, flat) 73/27 0.01
Aluminum (polished plate) 400/227 0.04
1070/577 0.06
Aluminum (rough plate) 78/26 0.06
Aluminum (oxidized) 390/199 0.11
1110/599 0.19
Aluminum surfaced roofing 100/38 0.22
Tin (bright tinned iron sheet) 77/25 0.04
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Nickel wire 368/187 0.10
Lead (99.95% pure, unoxidized) 260/127 0.06
opper 390/199 0.18
1110/599 0.19
Steel 390/199 0.52
1110/599 0.57
Zinc (galvanized sheet iron, bright) 82/28 0.23
Brass (highly polished) 476/247 0.03
Brass (hard rolled, polished w/lines) 70/21 0.04
Iron galvanized (bright) ——- 0.13
Iron plate 68/20 0.69
Rolled sheet steel 71/21 0.66
Oxidized iron 212/100 0.74
Wrought iron 70/21 0.94
Molten iron 2550-3270/1299-1399 0.29
opper (polished) 70-242/21-117 0.02
opper (scraped, shiny, not mirrored) 72/22 0.07
ooper (plate,
Brick (red, rough) 70/21 0.93
Brick (silica, unglazed rough) 1832/1000 0.80
oncrete ——— 0.94
Glass (smooth) 72/22 0.94
Granite (polished) 70/21 0.85
Marble (light gray, polished) 72/22 0.93
Asbestos board 74/23 0.96
Asbestos paper 100/38 0.93
700/371 0.95
Asphalt (paving) 39/4 0.97
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14
MAKING ACCURATE MEASUREMENTS
The IRT105 has a distance-to-spot (D:S) ratio of 6:1. This
means that the target area (spot) whose infrared radiation
(temperature) is being measured increases in diameter by
1 inch for every 6 inches you move away from the target.
onversely, the diameter of the target area measured
decreases by 1 inch for every 6 inches you move closer to
the target.
All IR thermometers (IRTs), including the IRT105, take the
average temperature of all objects within a circular target
area (spot). Although the distance “D” in the D:S ratio is
defined as a linear value and the “S” defines the diameter of
the spot (see Fig. 4), the critical parameter is the target area.
Depending on the distance to the target (the object whose
temperature you want to measure), the target area may
include both the target and background objects near or
behind the thermometer’s field of view, which defines the
target area or spot.
Fig. 4. The IRT105’s field of view

To explain the relationship between D:S ratio and
measurement accuracy, consider how the IRT105 would be
used to measure the temperature of a small A motor
suspected of overheating. The motor measures approximately
1 ft x 1 ft, so it has an area of 1 ft2. If the IRT105 is used to
make the measurement from 12 ft. away, the reading will
have a large error. At this distance, the target area is 2 ft2.
Therefore, the IRT105 will measure not just the temperature
of the motor, but also the temperature of the physical
surroundings in its field of view (see Fig. 5, top), and average
the two readings.
How inaccurate would the measurement be? If the motor’s
operating temperature is 200°F and the background
temperature is 75°F, and the motor’s area is half the target
area at the measurement distance, the following equation
gives the average temperature of the target area:
Tavg = (Tmotor + Tbackground) ÷ 2
Solving for Tavg, we get (200 + 75) ÷ 2 or 137.5°F., which is
what the IRT105 would display. In other words, trying to
measure the temperature of the motor from 12 ft. away
introduced an error of (200-137.5) ÷ 200, or 31% into the
measurement. In this case, the measured temperature was
31% below the motor’s actual temperature because the
background is cooler than the motor.
15

To eliminate measurement error, the IRT must be moved close
enough so the motor is the only object in the target area (see
Fig. 5, bottom). For a motor with an area of 1 ft2and using the
IRT105, with a D:S ratio of 6:1, the optimum measurement
distance would be 6 ft.
Fig. 5. Measuring a motor’s temperature from the wrong
(top) and right (bottom) distance.
16

SPECIFICATIONS
Measurement Range -22° to 482°F (-30° to 250° )
Measurement Accuracy ±3°F (2° ) or 2% of reading
(whichever is greater) above 32°F
(0° ); ±5°F (3° ) or 2% of reading
(whichever is greater) below 32°F
Measurement Repeatability 1% of reading or 1°
Distance-To-Spot (D:S) Ratio 6:1
Emissivity Adjustable from 0.1 to 1 in 0.01
increments (factory set to 0.95)
Response Time 500 msec for 95% response
Display Type/Size/Resolution L D/1.0 x 0.8 in.
(25 x 19mm)/±0.1°
Laser lass/Power/Wavelength lass 2<1mW/655nm
Response Wavelength 8 to 14 um
Auto Power Off After 15 seconds of inactivity
Thermometer Battery Life 50 hours, typical
urrent onsumption <5mA w/laser off
Operating Temperature 32° to 104°F
(0° to 40° )@<75% R.H.
Storage Temperature -4° to 140°F
(-20° to 60° )@<85% R.H.
Dimensions 4.25 x 2.05 x 0.98 in.
(108 x 52 x 25mm)
Weight 1.41 oz. (40g)
Power Source Two R2032 (3V) non-
rechargeable Lithium-ion cells
17

WARRANTY INFOR ATION
General Tools & Instruments’ (General’s) IRT105 6:1 Pocket
Infrared Thermometer is warranted to the original purchaser
to be free from defects in material and workmanship for a
period of one year. Subject to certain restrictions, General will
repair or replace this instrument if, after examination, the
company determines it to be defective in material or
workmanship. The warranty period begins on the date of
purchase. You are encouraged to register your product online.
General will extend your warranty an additional 60 days if you
register at www.generaltools.com/Product Registry.
This warranty does not apply to damages that General
determines to be from an attempted repair by non-authorized
personnel or misuse, alterations, normal wear and tear, or
accidental damage. The defective unit must be returned to
General Tools & Instruments or to a General-authorized
service center, freight prepaid and insured.
Acceptance of the exclusive repair and replacement remedies
described herein is a condition of the contract for purchase of
this product. In no event shall General be liable for any
incidental, special, consequential or punitive damages, or for
any cost, attorneys’ fees, expenses, or losses alleged to be a
consequence of any damage due to failure of, or defect in any
product including, but not limited to, any claims for loss of
profits.
Register now at www.generaltools.com/ProductRegistry to
receive a 60-day extension to your warranty.
18

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 ustomer
Service to obtain an RGA (Return Goods Authorization)
number before forwarding the unit via prepaid freight to the
attention of our Service enter 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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6:1 TERMÓMETRO
INFRARROJO
DE BOLSILLO
MANUAL DEL USUARIO
IRT105
Lea cuidadosamente el manual antes de utilizar este producto.