Abstract: A robust gas sensor can be manufactured in a simple manner and at low cost, and have no movable optical components. A measured gas cell (3) has a wall defining a cylindrical space with a measured gas inlet. The measured gas cell (3) is limited in the longitudinal axial direction by a reflective, flat first cover element (1) and by a reflective, flat second cover element (5) arranged at a spaced location from and in parallel to the first cover element (1). The height of the measured gas cell (3) corresponds approximately to 1 to 3 times the diameter of the cover elements (1, 5). The second cover element (5) accommodates a radiation source (6) and two detector elements (23, 24) with at least one measuring detector and one reference detector. The radiation source (6) is arranged displaced by 30% to 60% of the radius of the second cover element (5) from the center of the second cover element (5).

Abstract: An optical gas sensor has a compact design and without movable optical elements, with at least one radiation source (8), at least one measuring detector (9, 12) and a reference detector (11). The reflecting measuring cuvette is designed as an annular space (1) between a first, inner cylinder section (6) and a second, outer cylinder section (2) that is concentric thereto. The annular space (1) is limited by a cover element (5) and a bottom element (7) arranged at a spaced location therefrom in the direction of the longitudinal axis. The cover element (5) is permeable to the measuring gas. The bottom element (7) accommodates the radiation source (8).

Abstract: A breath alcohol measuring apparatus includes a sample intake channel (7) for receiving the respiratory gas sample and a temperature sensor mounted in the sample intake channel (7). The breath alcohol measuring apparatus is so improved that the influence of the mouthpiece on the detection of the temperature of the respiratory gas sample is substantially eliminated. The temperature sensor is configured as an infrared optical thermometer (14) with a filter (10) transmissive for the infrared radiation. The filter (10) is disposed in the sample intake channel (7).

Abstract: An optical gas sensor has a compact design and without movable optical elements, with at least one radiation source (8), at least one measuring detector (9, 12) and a reference detector (11). The reflecting measuring cuvette is designed as an annular space (1) between a first, inner cylinder section (6) and a second, outer cylinder section (2) that is concentric thereto. The annular space (1) is limited by a cover element (5) and a bottom element (7) arranged at a spaced location therefrom in the direction of the longitudinal axis. The cover element (5) is permeable to the measuring gas. The bottom element (7) accommodates the radiation source (8).

Abstract: An infrared optical gas sensor is improved with respect to the quality of the measured signal. The infrared radiation detectors (4, 6) used as the reference radiation and measuring radiation detectors include thin layers of a partially transparent material, which sends an electric measured signal that depends on the radiation intensity received. The infrared radiation detectors are arranged stacked one over the other and with an interposed narrow-band filter (3, 5) each, which are transparent at the measuring wavelength. The infrared radiation detectors have an electrically conductive coating on the top side and the underside and are contacted.

Abstract: An infrared optical gas sensor is improved with respect to the quality of the measured signal. The infrared radiation detectors (4, 6) used as the reference radiation and measuring radiation detectors include thin layers of a partially transparent material, which sends an electric measured signal that depends on the radiation intensity received. The infrared radiation detectors are arranged stacked one over the other and with an interposed narrow-band filter (3, 5) each, which are transparent at the measuring wavelength. The infrared radiation detectors have an electrically conductive coating on the top side and the underside and are contacted.

Abstract: The invention is directed to a method of operating a laser diode in a measuring system for spectroscopically measuring the concentration of a gaseous component in a gas sample. This method is improved in that the mode jumps of the laser diode are easily recognized when adjusting the temperature-current operating point of the laser diode. An optical filter is placed in the beam path for adjusting the temperature-current operating point of the laser diode and, by changing the temperature T and the operating current I of the laser diode while simultaneously receiving the output signal supplied by an evaluation unit, the spectral positions of the mode jumps of the laser diode are determined which are included in the absorption lines of the gas sample. Thereafter, the temperature-current operating point is adjusted so that the distance of this operating point to the positions of the mode jumps is not less than a fixed spacing.