Meter Description; Operating Instructions; Over-Range Indicator; Measurement Notes - Extech Instruments 42540 User Manual

Meter Description

1. Laser pointer beam
2. IR Sensor
3. Measurement Trigger
4. Battery Compartment
5. LCD Display
6. Push-buttons
7. Handle Grip

Operating Instructions

1. Hold the meter by its Handle Grip and point it toward the surface to be measured.
2. Pull and hold the Trigger to turn the meter on and begin testing. The display will light if
the battery is fresh. Replace the battery if the display does not light.
3. While continuing to pull the Trigger:
a. Push the laser button
laser icon
beam at the point of test (pressing the laser button again turns the laser off).
b. Select the temperature units using the
c. Push the backlight button
4. Release the Trigger (the reading will hold for approximately 6 seconds) and the meter
will automatically shut off.

Over-range Indicator

If the temperature measurement exceeds 1400°F (760°C), the thermometer will display
dashes in place of a temperature reading.

Measurement Notes

1. The object under test should be larger than the spot (target) size calculated by the field
of view diagram.
2. If the surface of the object under test is covered with frost, oil, grime, etc., clean before
taking measurements.
3. If an object's surface is highly reflective, apply masking tape or flat black paint to the
surface before measuring.
4. The meter may not make accurate measurements through transparent surfaces such
as glass.
5. Steam, dust, smoke, etc. can obscure measurements.
6. The meter compensates for deviations in ambient temperature. It can, however, take
up to 30 minutes for the meter to adjust to extremely wide ambient temperature
changes.
7. To find a hot spot, aim the meter outside the area of interest then scan across (in an up
and down motion) until the hot spot is located.
to turn on the laser pointer. When the laser is on, the
will appear on the LCD over the temperature reading. Aim the red
to turn on the LCD backlight function.
1
2
3
4
o o
C or F button.
3 Model 42540 Version 1.3 January 2004
5
6
7