Abstract: A pyrometric measurement method and a multi-channel pyrometer for determining the temperature T.sub.o of surfaces with different emissivities by measuring the spectral signal voltages U.sub.j at j=1 to n effective wavelengths. The invention obtains, by infrared measurements at at least two effective wavelengths, information concerning the object temperature and the emissivity relationships actually existing for selected surface materials, such as those which are typical for a user. The spectral signal voltages U.sub.ij are ascertained as a function of the difference U.sub.oj -U.sub.uj for a discrete number i=1 to n of surface materials differing in emissivity and the hypothetically possible spectral voltages U.sub.oij and, from these, the probable object temperature T.sub.o and the probable applicable surface material are determined from the measured spectral signal voltages U.sub.j, using the functional relationship that has been established for each emissivity .epsilon..sub.ij.

Abstract: A method for the contactless measuring of the temperature of objects with a hanging proportion of differently emitting surfaces having the same temperature by means of a multi-channel pyrometer, for example, for pyrometric measurements, on which there are different amounts of residues of the material to be processed. The spectral signal voltages U.sub.ij are ascertained as a function of the difference U.sub.oj -U.sub.uj for the i=1 to m surfaces of the object differing in emissivity, at least m spectral signal voltages U.sub.j are measured and the object temperature is determined from the additive superimposition of the m radiation sources in the measurement location.