Investigation of metrological characteristics of indirect measurements of emissivity and temperature by linear method

Abstract

The article is devoted to metrological characteristics increase of two-color compensative thermometry by clarifying its adjustment using the linear method of indirect measurements of emissivity. The aim of the article is to investigate the influence of radiative characteristics (determinative factors) of the thermometered object on methodical errors of indirect emissivity and temperature measurements. The formulae and graphic representations of complex influence of object radiative characteristics on errors of indirect emissivity and temperature measurements have been obtained. Higher metrological characteristics of two-color compensative thermometry with clarified adjustment by linear method, compared with apriori averaged adjustment, have been established. Thus, in the case of linear emissivity spectral distributions the errors of emissivity and temperature measurements are excluded. At the values of object factors that correspond to tungsten, the linear method, in comparison with limit conditions at averaged apriori adjustment, allows the emissivity measurement error to be reduced 3,8 times, and the temperature error – by 4,8 times. Two-color compensative thermometry with clarified adjustment widens the application field of non-alternative for the most effective resource-saving continuous high-temperature thermal control optical thermometry in the conditions of unknown and randomly variable optical characteristics of objects of control in energetics, metallurgy, glass, refractory, and other industries. Developed thermometry methods can also be utilized for aerospace research and control. Keywords: two-color compensative thermometry, linear method, equation and nonlinearity coefficient of emissivity spectral distribution, temperature, methodical error