测试与检测技术基础----25.ppt

Fundamentals of Measurement Technology(11)
Prof. Wang Boxiong
Infrared radiation detection
Fig. ic radiation spectrum
Infrared radiation detection
The relationship between an object’s temperature and radiation power are described by Stefan-Boltzmann’s law:
Infrared radiation detection
The Planck’s Law describes the radiation intensity distribution for an ideal radiator (blackbody) under different temperatures:
Infrared radiation detection
If we should heat an ideal radiator to various temperatures and determine the relative intensities at each wavelength, we would obtain characteristic energy-distribution curves such as those shown in Fig. . Not only is the radiation intensity of the higher-temperature body increased, but the wavelength of maximum emission is also shifted toward shorter waves (from red toward blue).
Infrared radiation detection
Fig. Graphical representation illustrating the basis for Wien’s displacement law
Infrared radiation detection