Gas sensor for determining concentration of target gas in measurement gas e.g. industrial process gas, has resonant portion that is excited by photo-acoustic signal in reference gas volume so that resonant portion is oscillated

摘要

The gas sensor (1) has a search gas volume (11) and a reference gas volume (12) which are arranged with respect to each other so that electromagnetic radiation (30) from source (3) is penetrated through the search gas volume and reference gas volume. The resonant portion (2) is excited by photo-acoustic signal in the reference gas volume so that resonant portion is oscillated. An interferometer is provided for detecting the oscillation of the resonant portion. An independent claim is included for method for determining concentration of target gas in measurement gas.