EXTECH EX840 [8/12] Non contact infrared temperature measurements

EX840-EU-EN-V5.3-3/12

Non-Contact InfraRed Temperature Measurements

1. Set the function switch to the IR Temp position.

2. Aim the infrared sensor (rear of the meter) at the surface to

be measured.

3. Press the

button in the center of the rotary function

switch to turn on the laser pointer and identify the surface

spot to be measured.

4. The area of the surface to be measured must be larger

than the spot size as determined by the distance to spot

size specification.

5. Read the temperature in the display.

Note: See the “Temperature Units” paragraph to select

F or

WARNING: Do not directly view or direct the laser pointer at an eye.

Low power visible lasers do not normally present a hazard, but may

present some potential for hazard if viewed directly for extended periods

of time.

IR Spot to Distance Diagram

The 8:1 spot to distance ratio determines the size of the measured surface area with respect to the

distance the meter is held away from the surface.

IR 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. 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.

10cm

1.25cm

20cm

2.5cm

60cm

7.5cm

Distance to object

Diameter of spot