FIELD: prevention of fire. SUBSTANCE: pre-fire situation is determined by infra-red spectroscopy method by the effect of thermal destruction on products within three ranges of wavelengths characterized by the absorption of carbon-containing, chlorine-containing and oxygen-containing radicals and molecules. The device has an optical unit including a radiation source, multiway vessel, gas-and-air medium pumping facility, shadow and mirror modulators, slits, narrow-band filters, measurement result receivers, and single processing circuit with a source data unit. EFFECT: more reliable pre-fire diagnostics. 4 cl, 2 dwg
