Abstract: An apparatus for monitoring whether the combustion system of a gas turbine is working properly includes an annular array of temperature sensors disposed in the gas turbine to monitor the temperature of the hot gas stream at a plurality of spaced positions and a temperature sensor disposed in the gas turbine to monitor the temperature of the compressor discharge flow, a digital computer, a circuit to input signals indicative of the sensed temperatures of a selected sensor to the digital computer, and a circuit for selecting the temperature sensor to be sampled. The digital computer is programmed to sequentially sample the hot gas stream sensors and to determine the median temperature thereof, compute allowable temperture limits as a function of the median temperature and the compressor discharge temperature, and to output a shutdown or alarm signal when a predetermined number of hot gas stream temperature sensors exceed the allowable limits in a predetermined pattern.

Abstract: An arrangement for determining the validity of temperature sensor readings of a gas turbine hot gas stream which includes means for comparing each reading to predetermined bounds. The temperature sensors are arranged so that a temperature streak caused by a combustion system malfunction would affect more than one sensor. In some cases, when a suspect reading is identified, the readings from adjacent sensors are examined before the suspect reading is rejected.