Abstract
The paper considers the issues of creating high-temperature digital thermographs based on RGB photodetector arrays. It has been shown that increasing the reliability of temperature measurement of bodies with unknown spectral coefficient of thermal radiation can be ensured by optimal selection of the used spectral range and registration of the observed thermal radiation fields in three spectral ranges. The registration of thermal radiation in four or more spectral ranges was found to be inefficient due to the increasing error in temperature determination. This paper presents a method for forming three overlapping spectral regions in the NIR spectral range, which is based on the use of an external spectral filter and a combination of the spectral characteristics of an RGB photodetector array. It is shown that it is necessary to ensure the stability of the solution of the system of three nonlinear equations with respect to the influence of noise. For this purpose, the use of a priori information about the slope factor of the spectral dependence of the thermal radiation coefficient in the selected spectral range for the controlled bodies is proposed. The theoretical results are confirmed by examples of their application in a thermograph based on an array of CMOS RGB photodetectors.
Highlights
Today’s product quality requirements impose a mandatory control of the conditions under which manufacturing processes are carried out
When the metal is heated to high temperatures, its surface roughness degree, its oxidation by atmospheric oxygen, presence of impurities, etc. can lead to a substantial change of spectral dependence of thermal radiation coefficient ε (λ) in comparison with the tabular values given in reference books
It will be necessary to take into account the dependence thepractice, statistical product b(λ − λ2) < 0.05, which is the case for many structural materialsofin the parameters of the noise of the photodetector channel of the three-spectral thermograph on exponential expression can be simplified by expanding the exponent in a power series and the value ofterms the incident fluxes greater of thermal discarding with powers thanradiation
Summary
Today’s product quality requirements impose a mandatory control of the conditions under which manufacturing processes are carried out. The non-contact methods based on the registration of thermal radiation emitted by the surface of the heated product seem to be the most convenient ones for controlling the temperature of complex thermal processes. In large enterprises, when controlling processes with stably repeating parameters (for example, rolling mills), presence the deviation of the illumination, partial radiation. This is especially truethe for specified values isthermography, usually used, since thermal processes are stable. In high-temperature wherethe theparameters techniques of recommended by manufacturers of the case of new complex processes, is desirable real infrared thermal imagingthermal equipment [1,4] tohowever, eliminateit the influencetoofdetermine unknownthe factors are inapplicable due to the high of objects.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
