FLIR T460 - Page 12

Table of contents
31 Glossary ...................................................................................... 129
32 Thermographic measurement techniques ........................................ 132
32.1 Introduction ........................................................................ 132
32.2 Emissivity............................................................................ 132
32.2.1 Finding the emissivity of a sample.................................. 132
32.3 Reflected apparent temperature............................................... 135
32.4 Distance ............................................................................. 135
32.5 Relative humidity .................................................................. 135
32.6 Other parameters.................................................................. 135
33 History of infrared technology......................................................... 137
34 Theory of thermography................................................................. 140
34.1 Introduction ......................................................................... 140
34.2 The electromagnetic spectrum................................................. 140
34.3 Blackbody radiation............................................................... 140
34.3.1 Planck’s law .............................................................. 141
34.3.2 Wien’s displacement law.............................................. 142
34.3.3 Stefan-Boltzmann's law ............................................... 143
34.3.4 Non-blackbody emitters............................................... 144
34.4 Infrared semi-transparent materials........................................... 146
35 The measurement formula.............................................................. 147
36 Emissivity tables ........................................................................... 151
36.1 References.......................................................................... 151
36.2 Tables ................................................................................ 151
#T559879; r. AH/23788/24627; en-US
xii