Method and apparatus for the detection of reducing gases in a gaseous mixture

Abstract

Abstract Reducing gases in a gas mixture to be tested, in particular in air, can be detected with increased sensitivity and precision by means of a gas detector (100) in which a gas sensor (11) is mounted in a measuring chamber (7) and the gas to be tested is periodically replaced by a pure reference gas from a reference chamber (5). The output signal of the gas detector (100), which is based on the variable electrical conductivity of the gas sensor (11) is measured during a multiplicity of gas replacement periods (27). Said output signal is made up of a direct-voltage signal and an alternating-voltage signal having the frequency of the gas replacement period. Using characteristics of the gas sensor (11), the presence of a particular reducing gas, preferably is exact concentration, can be determined in the presence of other reducing gases from the amplitude (66) of the alternating-voltage signal and the direct-voltage signal (65). <IMAGE>

Inventors

• 👤 Martin Forster
• 👤 Sigfrid Strässler
• 👤 Gustav Pfister
• 👤 Jakob Eberle

Bibliographic Details