摘要 |
The invention concerns a multi-wavelength pyrometer for the measurement of the temperature and emissivity of a surface above 900 K. The pyrometer has several radiation detectors sensitive in different wavebands lambda 1... lambda i... lambda n as well as a data processor to which the detector outputs are fed after digitalization and which calculates the temperature of the surface from these detector outputs using Wien-Planck's law, assuming the surface is a perfect black body. The emissivity is then calculated, as a function of the temperature and the wavelength, from these calculated temperature values using an approximation method, and from this, the required temperature. The invention calls for the differences between the actual pyrometer signals and the signals which would be expected from the assumed emissivity and the temperature calculated from this emissivity to be determined for various approximations and various wavelengths. The approximation which gives, for all the wavelengths, the least sum of the squares of these differences is then selected. |