Omega Engineering OS550 Series, Руководство пользователя

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C-3
Appendix: Determining an Unknown Emissivity
C
Method 4
1. Paint a sample of the object material with flat black lacquer paint.
2. Set the emissivity to 0.97 and measure and record the temperature
of the painted portion of the sample material - Area
“
A
”
in Figure
C-1. Make sure that the painted area of object material fills the
FOV of the thermometer.
3. Aim the thermometer at another spot on the target - Area
“
B
”
in
Figure C-1.
4. Adjust the emissivity of the thermometer until the temperature
reading equals the temperature found in Step 2.
Method 5
1. Use this method where practical to measure objects at
temperatures above 500°F (260°C).
2. Drill a 1.5
"
(35 mm) diameter hole in a sample of the object
material to a depth of 5
"
(127 mm). This hole closely resembles a
blackbody (refer to Appendix A).
Figure C-2. Determining Emissivity with a Drilled Hole
3. Set the emissivity to 0.97 and measure and record the temperature
of the hole in the sample material - Area
“
A
”
in Figure C-2. Make
sure that the hole fills the FOV of the thermometer.
4. Aim the thermometer at another spot on the target as close as
possible to Area
“
A
”
(Area
“
B
”
in Figure C-2).
5. Adjust the emissivity of the thermometer until the temperature
reading equals the temperature found in Step 3.
Drilled out
Area “A” Target
Area “B” Target