In this paper, we consider problems related to the verification of integral thermal radiation spectrum mathematical model for particles of gas-thermal jet used for spraying of protective coatings on technical parts. Previously developed optoelectronic thermal radiation simulator for gas-thermal spraying jet particles has been used and improved to confirm the adequacy of integral thermal radiation spectrum mathematical model to the experimental spectrum, recorded by a linear photodetector at the output of spectrophotometer measuring channel. Simulation of gas-thermal jet particles thermal radiation is provided by a radiator constructed as a group of miniature electric bulbs closely fixed to each other. A temperature distribution histogram of emitting elements is formed by splitting the electric bulbs into subgroups and setting the desired value of electric current for each subgroup, thus providing the desired temperature. The results of simulated experiments confirm the adequacy of integral thermal radiation spectrum model for particle flow.