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7. NOTES:
• How it Works
Infrared thermometers measure the surface temperature of an object. The
unit’s optics sense emitted, reflected, and transmitted energy, which is
collected and focused onto a detector. The unit’s electronics translate the
information into a temperature reading which is displayed on the unit. In
units with a laser, the laser is used for aiming purposes only.
• Field of View
Make sure that the target is larger than the unit’s spot size. The smaller
the target, the closer you should be to it. When accuracy is critical, make
sure the target is at least twice as large as the spot size.
• Distance & Spot Size
As the distance (D) from the object increases, the spot size (S) of the area
measured by the unit becomes larger. See: Figure 1 on Page 1.
• Locating a Hot Spot
To find a hot spot, aim the thermometer outside the area of interest, then
scan across with an up and down motion until you locate hot spot.
• Reminders
1 — Not recommended for use in measuring shiny or polished metal
surfaces (stainless steel, aluminum, etc.) See Emissivity below.
2 — The unit cannot measure through transparent surfaces such as glass.
It will measure the surface temperature of the glass instead.
3 — Steam, dust, smoke, etc., can prevent accurate measurement by
obstructing the unit’s optics.
• Emissivity
Most (90% of typical applications) organic materials and painted or oxi-
dized surfaces have an emissivity of 0.95 (pre-set in the unit). Inaccurate
readings will result from measuring shiny or polished metal surfaces. To
compensate, cover the surface to be measured with masking tape or flat
black paint. Allow time for the tape to reach the same temperature as the
material underneath it. Measure the temperature of the tape or painted
surface.
