About the article
L.V. ILYASOV, Dr. Sc.
The results of experimental studies aimed at revealing the operating principle of semiconductor ceramic gas concentration transducers are presented. The instructions for these converters (PP-1 and DMP-1) state that their principle of operation is based on an increase of the electrical conductivity of semiconductor ceramics at a temperature of 400–500 °C in the presence of reducing gases, in particular methane or propane. An experimental setup with a thermochemical pellistordetector and a research technique based on the use of a pulse method for entering samples of gases such as hydrogen, methane and propane, which made it possible to establish that catalytic combustion of these gases occurs in a semiconductor ceramic converter, and this causes an increase in the temperature of ceramics and its electrical conductivity are described. The dependences of the degree of catalytic combustion of gas on the sensing element of the semiconductor converter power supply voltage are obtained. It is proved that this sensitive element can change its electrical conductivity depending on the thermal conductivity of non-combustible gases such as nitrogen, helium, carbon dioxide. It is established that the sensitivity of the semiconductor converter of the concentration of combustible gases exceeds the sensitivity of the currently widely used pellistor detectors of combustible gases.
semiconductor, ceramic, converter, gas, electrical conductivity, catalytic combustion.