ISSN:
1432-0649
Keywords:
07.65b
;
43.20f
;
43.85e
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract A photoacoustic (PA) system for monitoring gaseous air pollutants absorbing in the CO-laser range is presented. The characteristics of the CO laser and the interference caused by water-vapor absorption demand a special design of the PA cell and experimental setup. The optimum cell design was found by numerical simulation of the acoustic properties of various cell geometries. For this purpose a model using infinitesimal analogue acoustic impedances was developed. Based on a matrix formalism for fourterminals, a computer program was applied that permits the calculation of the frequency response of the PA signal amplitude at any position within a one-dimensional PA cell. Excellent agreement with experimental data is obtained. As a result, a new design for an acoustically resonant spectrophone with improved properties is presented. The response of the cell with aQ-factor of 52, operated at 555 Hz, is 2000 Pa cm/W.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00694205
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