FLIR B6 series, User Manual

Page: 284 / 326

Measure the apparent temperature of the aluminum foil and write it down.
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Figure 32.4 Measuring the apparent temperature of the aluminum foil
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32.2.1.2 Step 2: Determining the emissivity
Select a place to put the sample. 1
Determine and set reflected apparent temperature according to the previous procedure. 2
Put a piece of electrical tape with known high emissivity on the sample. 3
Heat the sample at least 20 K above room temperature. Heating must be reasonably even. 4
Focus and auto-adjust the camera, and freeze the image. 5
Adjust Level and Span for best image brightness and contrast. 6
Set emissivity to that of the tape (usually 0.97). 7
Measure the temperature of the tape using one of the following measurement functions:
■
Isotherm (helps you to determine both the temperature and how evenly you have heated
the sample)
■
Spot (simpler)
■
Box Avg (good for surfaces with varying emissivity).
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Write down the temperature. 9
Move your measurement function to the sample surface. 10
Change the emissivity setting until you read the same temperature as your previous measure-
ment. 11
Write down the emissivity. 12
Note:
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Publ. No. 1558550 Rev. a557 – ENGLISH (EN) – October 7, 2011
32 – Thermographic measurement techniques