Fluke Ti20 - Manual (Page 35)

Basic Operation
Environmental Conditions
2
2-11
Best
Good
Incorrect
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Figure 2-4. Correct Field of View
Environmental Conditions
Watch for environmental conditions in the working area. steam, dust, smoke, etc.,
can prevent accurate measurement by obstructing the path between the target and the
Imager optics. Noise, electromagnetic fields, or vibration are other conditions that can
interfere with temperature measurements, and should be considered before starting
temperature measurements.
Ambient Temperature Derating and Thermal Shock
The Imager’s operating temperature range is 0 ° C to 50 ° C (32 ° F to 122 ° F). As ambient
temperature slowly deviates from 25 ° C (77 ° F) there is a derating or the Imager’s
accuracy specification by ± 0.2 ° C/ ° C or ± 0.2% / ° C whichever is greater. For
example, if the Imager was operating in an ambient temperature of 35 ° C, the accuracy
specification would be ± [2 + (35 - 25) x 0.2] = ± 4 ° C for temperatures less than 100 ° C
or ± [0.02 + (35 - 25) x 0.002] x T (temperature being measured) for temperatures greater
than 100 ° C.
The Imager will work accurately even when subjected to sudden ambient temperature
change as large as ± 25 ° C ( ± 45 ° F) of more (going from a room at 25 ° C to a freezer
room at 0 ° C). For the most accurate readings, you should:
• Wait ~ 2 minutes after a large ambient shock (greater than 10 ° C) before making
any readings.
• Turn the Imager on and then wait 3 seconds.
• For smaller ambient shocks (10 ° C change or less) no special precautions are
necessary.