J. Phys. IV France 129 (2005) 125-129
Frequency characteristic of an optopneumatic detectorK. Jasek1, B. Mazurek1 and M. Pasternak2
1 Institute of Chemistry, Military University of Technology, 00-908 Warsaw, Poland
2 Institute of Radioelectronic, Military University of Technology, 00-490 Warsaw, Poland
In this paper, a single-beam optopneumatic detector with two chambers was considered. On the base of a mathematical model its frequency characteristic was determined and an influence of various factors on amplitude of gas flow between the detector chambers was investigated. It was found that this flow appears as a result of a phase difference in pressure oscillations at both chambers. According to the assumed model the signal from the detector should rich a maximum value within the range of about 1-100 Hz but an examined detector shows the signal decreasing from 1 Hz. It is caused by large time constant of a sensor measuring the flow between the detector chambers.
© EDP Sciences 2005