Temperature and spectral emissivity measurement of the metallic thermal protection blanket based on multi-wavelength thermometry

Based on the reference temperature model of multi-spectral thermometry, a kind of data processing method was introduced to solve the measurement problem of the metallic thermal protection blanket hot side temperature and emissivity in continuously heating course. A new emissivity assumption was presented in this paper. Based on the new assumption, a new data processing method of the multispectral radiation thermometer was introduced. The method was to assume that the temperature and emissivity had approximate identical linear relation in the spectrum. By processing the measured data of the multispectral pyrometer at two different times, the true temperature and spectral emissivity could be simultaneously calculated. The radiation of the metallic thermal protection blanket at 900-1300°C was measured by using a multispectral pyrometer. The results show that so long as the difference between the initial temperature value and the measured target temperature is within ∓200°C, the calculated values of the true temperature and spectral emissivity are in good agreement with that of the measured targets. The total uncertainty is less than 2%. The above-mentioned method is a practical method for the metallic thermal protection blanket temperature and emissivity measurement.