FIELD: quantitative IR spectrometry of gas mixtures. SUBSTANCE: process of determination of content of ammonia in gas mixture lies in action in turn on analyzed gas mixture and standard mixture without ammonia with pulses of laser radiation with characteristic and noncharacteristic lengths of waves in IR region of spectrum, in measurement of amplitude of one of odd Fourier harmonics of radiation intensities passed through both gas mixtures. Concentration of ammonia is evaluated by difference of amplitudes of odd Fourier harmonics. For increase of accuracy of process amplitudes of even Fourier harmonics are measured and corresponding odd Fourier harmonics are normed on them. Device for implementation of process includes pulse laser with length of wave returnable within IR region of spectrum. Two light splitters directing radiation along three branches are placed in radiation path of it. Dish with analyzed mixture is installed in one branch, behind it there are positioned return mirror and detector which is hit with radiation passed through dish. Second branch has dish with standard mixture without ammonia, detector is located behind it. Third branch includes dish with known content of ammonia and detector. Outputs of detectors are connected to three identical electric circuits designed to isolate amplitudes of odd and even Fourier harmonics of intensities of radiation passed through dishes. Outputs of circuits are linked to control unit. EFFECT: high sensitivity and accuracy of measurement of content of ammonia in gas mixtures. 12 cl, 5 dwg
