Gas turbine plant and method of operation

In a method for operating a gas turbine plant (10) with a compressor (11) for the compression of combustion air sucked in from the surroundings, with a combustion chamber (15) for generating hot gas by the combustion of a fuel with compressed combustion air, and with a turbine (12), in which the hot gas from the combustion chamber (15) is expanded so as to perform work, temperatures and pressures are measured at various points in the gas turbine plant (10), and a combustion chamber exit temperature is derived from the measured temperatures and pressures and used for controlling the gas turbine plant (10). Improved temperature determination is achieved in that the composition of the gas, in particular the water content in the exhaust gas of the turbine (12), is determined, and in that the specific water content in the exhaust gas of the turbine (12) is taken into account in deriving the combustion chamber exit temperature.