Optoacoustic measuring arrangement and use thereof

Abstract

The measuring arrangement contains a measuring cell and a reference cell (9, 10), respectively, and microphones (11 and 12) assigned to these cells, to which microphones an electronic evaluation circuit (7, 8) is connected and in which a subtraction of the signals of the microphones (11 and 12) takes place, as well as a radiation source (5) for applying a modulated signal to the measuring cell (9). The modulation frequency of the radiation source (5) coincides with the resonant frequency of the measuring cell (9), and the measuring cell and the reference cell (9 and 10) are open at at least one end to the gas and/or aerosol to be detected. The measuring arrangement is used as smoke alarm, gas alarm, fire hazard alarm or as combined smoke and gas alarm, wherein each of the measuring cells (9) is exposed to a radiation of a wavelength at which a relevant substance to be detected is absorbent and an opto-acoustic effect is produced as a result.

Dependencies are inferred from the claim text.