Abstract: A pyrometer system for use in measuring the temperature of components in an operating jet engine corrects for random interference in the pyrometer temperature signal caused by radiation from the combustor flame. An optical beam from a periodically moving target engine component such as a turbine blade is provided to a detector module which splits the beam into two beams, one of which has a spectral width less than that of the target beam. Temperature signals are generated by a multiple spectral area pyrometer which are provided to a signal processor for correction. The signal processor compares present target temperature signal values sampled at selected phases during the target period with corresponding ones taken in an earlier period. Previous signals are averaged or replaced with current values if these meet criteria involving one or two temperature signals, noise band and magnitude.

Abstract: An optical pyrometer for use with jet engines is characterized by the use of three spectral areas or bands in a temperature computation. A target temperature is optically distinguished from background radiation by dividing a received optical beam into three spectral components which are comprised of emitted and reflected radiation. A controller computes the measured power in each band as a function of the emitted power by the target and a ratio of reflected power in adjacent bands to yield signals of reflection corrected radiation. These are used with the reflected power ratios to determine values of temperature in adjacent bands. The difference between these computed temperatures is iteratively adjusted until the difference therebetween is approximately equal to a preselected value.

Abstract: A high optical efficiency dual spectra pyrometer for measuring the temperature of a target includes an optical guide for collecting and guiding a target optical beam to a detection module which comprises an interference filter and photodetectors adjustably positioned to provide efficient coupling of the target optical beam thereto. The pyrometer additionally includes a signal processor which receives the signals from the photodetectors, as well as signals indicative of an estimated fireball equivalent black body temperature and the spectral width difference between the two detector signals, and provides a compensated temperature signal.

Abstract: A reflection corrected radiosity optical pyrometer includes an optical guide for receiving a target optical beam from a turbine blade in a jet engine. The target optical beam is provided to a detector module that divides the target optical beam into two beams, one having a spectral width selected to be less than the target optical beam spectral width. A signal processor receives signals from the detector module indicative of the energy of the two beams, calculates a reflection corrected energy signal directly therefrom and provides a correct target temperature signal.

Abstract: A dual spectra optical pyrometer having an air pressure sensitive shutter for measuring the temperature of a turbine blade includes a sight tube located in the jet engine receiving an optical beam from the turbine blade. Located within the sight tube is a shutter responsive to the jet engine air pressure and providing the turbine blade optical beam only above a selected threshold magnitude of said air pressure. A detection module receives and divides the turbine blade optical beam and provides signals to a signal processor. From these signals and signals indicative of an estimated fireball equivalent black body temperature and the spectral width difference between the two detector signals, the signal processor provides a signal indicative of a compensated turbine blade temperature.

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.