Abstract: A gas concentration-measuring device makes it possible to measure gas components in a gas sample. An interferometer, based on a dual-band Fabry-Perot interferometer (1), is provided with a transmission spectrum that can be set by a control voltage (38). The control voltage (38) of the dual-band Fabry-Perot interferometer (1) is synchronized over the course of time with the activation and deactivation of the radiation sources (11, 12).

Abstract: A device for measuring the concentrations of paramagnetic gases in a gas sample has at least one modulatable magnetic flux source, which has an air gap, to which a gas sample can be fed. A controllable power source, for generating current and voltage signals, is coupled with the modulatable magnetic flux source in order to generate a modulatable magnetic flux within the air gap. Two measuring points are arranged at least partly within the air gap. Each measuring point has an electrically controllable heating device and a heat conduction-measuring unit or resistive measuring device. Each measuring point is coupled with a variable power source to heat the heating device to a working temperature. Each measuring point is coupled with a measuring circuit to measure heat conduction measured signals generated by the heat conduction-measuring unit, from which the concentrations of paramagnetic gases, which are contained in the gas sample, can be derived.

Abstract: A gas concentration-measuring device makes it possible to measure gas components in a gas sample. An interferometer, based on a dual-band Fabry-Perot interferometer (1), is provided with a transmission spectrum that can be set by a control voltage (38). The control voltage (38) of the dual-band Fabry-Perot interferometer (1) is synchronized over the course of time with the activation and deactivation of the radiation sources (11, 12).

Abstract: A gas concentration measuring apparatus is in miniaturized form and permits the measurement of anesthetic gas components. A variable interferometer is provided on the basis of a Fabry Perot interferometer (1) wherein the mirrors (2, 3) can be changed in spacing with respect to each other. The mirrors (2, 3) have coatings which make possible the transmission in two spectral ranges (??1, ??2).