Patent ID: 8342745

Claim:
A method for passive determination of an operating temperature in a thermally highly loaded device, comprising: providing a plurality of individual passive measurement elements, which have at least one measurable physical parameter that depends unambiguously on a constant temperature which is set during heat treatment of the measurement element or of a material which is used in the measurement element, and which parameter is set differently for each of the different measurement elements, combining the individual measurement elements to form an array such that the entire array is subjected to essentially only one temperature during the measurement of the operating temperature; determining, in a first measurement, values of the physical parameter for all the measurement elements in the array, before the array is subjected to the operating temperature to be measured; subjecting the array, over a time period, to the operating temperature to be measured in the device; determining, in a second measurement, values of the physical parameter for all the measurement elements in the array; and comparing the values of the physical parameter measured in the first and the second measurement for each of the measurement elements with one another and the temperature of the heat treatment of that measurement element whose value of the physical parameter has changed the least in the two measurements is taken as the measured temperature.