| 摘要 |
<p>A two stage process for interrogating a detector of the concentration of combustible gas in an atmosphere. In a first stage, the detector is supplied with a low voltage and the supply is cut and an optional alarm is sounded if a positive signal has been detected. In a second stage, if the signal detected in the first stage is negative or zero, then the detector is supplied with a second, higher voltage. The signal is compared to a predetermined range and, if not within that range, an optional alarm is sounded. A device to apply the process comprising a detector, an amplifier of the signal issued by the detector, a voltage reducing circuit, and a switch that controls the voltage reducing circuit slaved by a discriminator to the sign and/or to the maximum amplitude of the signal output by the amplifier. Application of the process and device to the detection of the concentration of methane.</p> |
