摘要 |
PCT No. PCT/FR90/00242 Sec. 371 Date Oct. 7, 1991 Sec. 102(e) Date Oct. 7, 1991 PCT Filed Apr. 5, 1990 PCT Pub. No. WO90/12313 PCT Pub. Date Oct. 18, 1990.To measure the concentration in a gaseous medium of a known combustible gas a resistive element in the gaseous medium having a catalytic surface or being sensitive to variations in the concentration of the combustible gas in the gaseous medium is electrically heated, the value of a parameter representative of the gas concentration is detected and there is deduced therefrom, using a conversion law obtained previously by calibration, a measurement of said concentration. The element is heated periodically in cycles comprising a heating phase, a second phase in which the intensity I is controlled in such a way as to maintain the resistive element at a set point temperature and the stabilized value of the voltage U at the terminals of the detector is measured, and a third phase in which the heating power is reduced. On average the power of the electric current flowing during the second phase is substantially less than the heating current power.
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