OPTOELECTRONIC_PYROMETER

Published:2009/6/24 4:19:00 Author:Jessie | From:SeekIC

This setup optically measures the temperature of an incandescent body. It makes use of the shift in the emission spectrum of a black body toward shorter wavelengths, as temperature is increased.Optical ffiters are used to split the emission spectrum, with one photodiode being illuminated by short wavelengths (visible light) and the other by long (infrared). The photocurrents are converted to logarithms by Q1 and Q2. These are subtracted to generate an output that varies as the log of the ratio of the illumination irttensiftes. Thus, the circuit is sensitive to changes in spectral distribution, but not intensity.



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