Abstract: Detector of the filament type for determining a static or dynamic characteristic of an ambient medium, constituted by a resistive component intended to be heated by the Joule effect in the medium, and an interface process region suitable for reacting with the medium by a physico-chemical with an effect, depending on the characteristic to be determined, on the electrical characteristic of the interface region, in which there is a supporting member through which there is at least one aperture and at least one filament including the resistive component, composed of one or more thin films and a central portion located in the aperture and end portions via which the central portion is connected to the supporting member.

Abstract: Detector of the filament type for determining a static or dynamic charactstic of an ambient medium, constituted by a resistive component intended to be heated by the Joule effect in the medium, and an interface region suitable for reacting with the medium by a physico-chemical process with an effect, depending on the characteristic to be determined, on the electrical characteristic of the interface region, in which there is a supporting member through which there is at least one aperture and at least one filament including the resistive component, composed of one or more thin films and a central portion located in the aperture and end portions via which the central portion is connected to the supporting member.

Abstract: 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.