Passive Fourier Transform Spectrometer
Equipment Accuracy:It has no built-in light source. It takes the inherent thermal radiation (blackbody infrared radiation) from the measured object, atmosphere and ground surface as incident light. The radiation enters a Michelson interferometer to generate interferograms, which are processed via FFT to obtain infrared spectra. Substances are identified by the temperature difference and radiation difference between targets and backgrounds.
Detailed Introduction: