Abstract: A novel dual spectra optical pyrometer is characterized by a serial array of photodetectors. The first photodetector absorbs a spectral portion of a target optical beam incident thereto, and passes the remainder optical beam to the second photodetector. Signals from both photodetectors are provided along with signals indicative of the first detector's spectral absorption and an estimate of the equivalent black body temperature of a fireball to a signal processor which provides a compensated temperature signal therefrom.

Abstract: A novel dual spectra optical pyrometer for use in in-flight control of jet engines includes an optical probe containing a shutter sensitive to the air pressure within the jet engine. The shutter provides an optical beam from rotating turbine blades to an optical fiber only above a threshold pressure. A serial array of photodetectors receives the optical beam and provides first and second signals therefrom. A signal processor receives the first and second signals as well as signals indicative of the energy ratio therebetween, and provides reflection corrected energy signals from the difference between the first signals and the product of the energy ratio signals and the second signals.