摘要： The simulation of high-speed electro-optical device for fire detection under the influence of dynamic optical interference on the entrance pupil is performed. The analysis of known approaches to providing noise immunity of the device is performed: use of selected spectral ranges of control; the use of additional channels of the device (hardware redundancy); the use of additional algorithms for signal processing channels of the device (software redundancy). Analytical dependences for modeling are formulated. The simulation is performed. Calculation of the mathematical model was made using software package Matlab and the development environment RAD Studio. The characteristics of changes in spectral ratios depending on the temperature of the filament body are obtained. The spectral flux of the incandescent lamp is calculated from the dynamics of the temperature change of the incandescent body. As result of modeling, the spectral ranges of control – 1350±50, 2700±50 and 4300±50 nm were selected, and their ratios were based. Ratios of Q2700-1350 for the spectral flow of a fire and incandescent bulbs made up 10.9 and 0.164 respectively. Ratios of Q2700-4300 hearth and bulbs amounted to 1.34 and 4.13, respectively. The values of the ratios established in the range for Q2700-1350 from 10.748 to 0.784 for Q2700-4300 from 1.354 to 1.557for total flow with changes lamp. The characteristic values of the ratios changes characterizing the fire and the incandescent lamp and allowing to detect the radiation of the source against the background of optical interference are determined. Additional studies on the basis of the developed model should be carried out to more accurately identify the source of fire under the influence of dynamic optical interference.