The photoacoustic gas analyzer utilizing an industrial carbon-dioxide waveguide laser was presented to quantitatively determine low concentration of gaseous pollutants in real air. The PA resonant H-type cell design was described. By analyzing the dependence of the PA signal on a modulation frequency, the most suitable acoustic resonance was chosen for practical use. The spectrophone characteristic constant A was determined for various carbon-dioxide laser lines which coincided with air pollutants absorption lines. The schematic diagram of the full- automatic PA gas analyzer was considered, and the interconnection of its units was outlined. It is shown that PA gas analyzer concentration characteristic is linear in a wide concentration range overlapping three orders of magnitude; pollutants detection threshold values are considerably less than their utmost admissible concentrations in air of the living zone. An idea of using Stark's modulation at atmospheric gas pressure analysis is examined.

Date Published: 22 April 1996
PDF: 5 pages
Proc. SPIE 2773, Laser Optics '95: Gas Lasers, (22 April 1996); doi: 10.1117/12.238516

Published in SPIE Proceedings Vol. 2773:
Laser Optics '95: Gas Lasers
Inna M. Belousova, Editor(s)