Measurement of basic radiation

1 radiation flux

The absolute measurement of the radiation flux is carried out by using the equivalent substitution principle of the DC t radiation flux. Equivalent replacement principle is the radiation heating surface with a thin black metal, compared with the DC electric heating the metal plate so that the temperature rise. When the temperature rises to be equivalent, and the size of the heat flux of sheet metal absorption required for large quantity of small equal. Measurement of temperature rise using absolute radiometer or no wavelength dependent detector for spectral responsivity.

2 irradiance and radiation intensity

The physical quantity of radiation intensity and radiation intensity is different, but the method is the same. The irradiance is measured using a calibrated radiation flux responsivity and the side of the radiation detector is known to have a known light area. Using this radiation detector, the radiation intensity at a specific distance is compared with the numerical value of the irradiance standard bulb with a scale effect.

3 radiance

The brightness of the radiation is measured by comparing with the spectral radiance standard bulb. The spectral radiance standard bulb is a tungsten filament lamp, which is determined by the comparison of the spectral radiant brightness of the central part of the strip with the known temperature in a quartz window.