Understanding Infrared Thermography Reading 3

1. The best way to determine the effective emissivity of a target surface is:
a. to look it up in a table.
b. to calcu late it.
c. to measure the effective emissivity of the material itself or a similar
sample.
d. all of the above.
2. For an opaque graybody target surface, emissivity equals:
a. 1/refleclivity.
b. 1-reflectivity.
c. 1.0.
d. reflectivity to the fourth power.
3. The effective emissivity of a surface is always affected by:
a. the material, its surface texture and the viewing angle.
b. the material, its thermal conductivity and humidity.
c. the material, its surface texture and its thermal diffusivity.
d. the material, its visible color and its thermal conductivity.
Charlie Chong/ Fion Zhang