42560 V5.0 8/08
7
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
As the distance from the object increases, the spot size of the area measured becomes
larger. The meter’s field of view is 30:1; in other words if the meter is 30 inches from the
target (spot), the diameter of the target must be at least 1 inch (see diagram below). 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.
15” 30”
45”
60”
0.5” 1.0” 1.5”
2.0”
( Distance to object )
( Diameter of object )
