Abstract: The apparatus for detecting the presence of a particular gas within a mixture of gases comprises first and second emitter means for emitting measurement and reference electromagnetic radiation beams respectively, which beams are activated in alternation, a measurement cell, a filter cell, first and second detector means for detecting electromagnetic radiation beams, a beam splitter, and acquisition and processing means for synchronously acquiring and processing the four signals US1, US2, UR1, UR2 delivered by the first and second detector means in succession when the first and second emitter means are respectively activated so as to determine the absolute concentration of the gas to be detected on the basis of the ratio R=(US1×UR2)/(US2×UR1) between the four signals, in which US1 and US2 respectively represent the signals delivered by the first and second detector means when the first emitter means is activated, and UR1 and UR2 respectively represent the signals delivered by the first and s

Abstract: This direct current power supply for electric vehicles includes a modular set of electrical storage batteries (16) which are electrically interconnected. The batteries are disposed in battery boxes (18, 20) which can be stacked to constitute a stack of modules (12, 14).

Abstract: In this method of analyzing a gas mixture containing at least one inflammable gas to determine its explosibility, a resistive heating element (15) is energized in an analysis enclosure (12) communicating with the gas mixture to be analysed to burn the gas mixture in the enclosure, an electrical signal (S) at the terminals of the resistive element (15) is measured during combustion, and the explosibility of the gas mixture is determined from a comparison of values of the signal measured during a transient phase in which the concentration of the inflammable gas in the gas mixture is falling. The measurements taken during the transient phase are taken at times chosen to obtain, for different inflammable gases, substantially identical measurement signals for concentrations corresponding to identical explosibilities.

Abstract: In this method of determining the concentration of a gas to be analyzed in a gas mixture, the value of a characteristic of the gas mixture having predetermined laws of variation as a function of temperature and of the gas concentration is calculated from at least one measured value of the intensity of at least one radiation transmitted through the mixture at ambient temperature, the value of the said characteristic at a reference temperature is determined from the law of variation of the characteristic as a function of temperature and the value of the gas concentration is determined from the law of variation of the said characteristic as a function of the concentration.

Abstract: Apparatus for detecting and signalling the presence of a dangerous gas in an atmosphere comprising means for detecting the gas and means for signalling when the gas content exceeds a predetermined level. Said detecting means and said signalling means are disposed in a common housing and connecting by a double-wire cable to a separate supply.