42545A-en-GB_V4.4 12/14
5
IR Measurement Notes
1. The object under test should be larger than the spot (target) size calculated by the field of view
diagram (printed on the side of the meter and in this guide).
2. Before measuring, be sure to clean surfaces that are covered with frost, oil, grime, etc.
3. If an object's surface is highly reflective, apply masking tape or flat black paint to the surface
before measuring. Allow time for the paint or tape to adjust to the temperature of the surface it is
covering.
4. Measurements through transparent surfaces such as glass may not be accurate.
5. Steam, dust, smoke, etc. can obscure measurements.
6. The meter automatically compensates for deviations in ambient temperature. However, it can
take up to 30 minutes for the meter to adjust to extremely wide 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.
Field of View
The meter’s field of view is 50:1. For example, if the meter is 50 inches from the target (spot), the
diameter of the target must be at least 1 inch. Other distances are shown in the field of view
diagram. Note that measurements should normally be made as close as possible to the device
under test. The meter can measure from moderate distances but the measurement may be affected
by external sources of light. In addition, the spot size may be so large that it encompasses surface
areas not intended to be measured.
25”
0.64m
36”
0.91m
50”
1.27m
100”
2.54m
0.5”
1.27cm
0.72”
1.83cm
1.0”
2.54cm
2.0”
5.08cm
Distance to object
Diameter of object
