Analysing gases by electroconductivity of semiconductors - for which gas is dopant, esp. for pollution level determn.

摘要

Gas is detected and analysed by contacting the medium contg. the gas with a semiconductor membrane for which the gas to analyse is a dopant. The variations in electrical conductivity of the doped semiconductor are measured. Specifically, an atmospheric pollution measurement appts. comprises a gas collector comprising a sealed enclosure which contains the semiconductor in teh forn of a thin membrane associated with an insulating support and an electrode system; a source of tension linked to the electrode system; and a measuring circuit with a high impedance entry enabling electrical conductivity measurements as a function of the content of the gas to be analysed. Pref. the semiconductor is a metal oxide. Process is simpler, quicker and more precise than previous methods.