FIELD: gas analyzing devices. SUBSTANCE: proposed gas analyzer is designed for analyzing basic environment polluting substances such as CO, HC, and NO contained in automobile exhaust gas and depends for its operation on infrared absorption of gases. Optical measurement section (high-quality steel tube) is used for recording measuring signals and reference signal by means of infrared radiation source and detector; value under measurement is obtained by ratio generation. Alarm signal is applied in response to excessive concentration of pollutants. On-board measuring system has modular devices such as sampling device, gas treatment device, analyzing device, and processing unit all incorporated in automobile design. Variable conditions occurring in automobile are compensated for by stiff mechanical design and correction of temperature deviations for which purpose first derivative is formed and signal level is finally set with aid of electronic gain control. Other capabilities of correction are calibration of neutral line with ambient air using changeover operations and also provision for tolerance field about noise signals in detector. EFFECT: facilitated detection of fault in combustion system. 10 cl, 10 dwg
