Abstract: A gas meter for determining a gas mixture consumption is revealed which determines sensor signal values proportional to a flow rate, this gas meter being calibrated as an energy measuring unit. The calibration is based on a basic gas mixture. During the measurement of the gas consumption, a measured energy consumption value is multiplied by a correction factor which takes account, at least approximately, of the calorific value of a supplied gas mixture, this calorific value being determined by an external unit. By this means, it is possible, using a simple and cost-efficient gas meter, to determine the effective supplied energy and to bill costs according to the supply.

Abstract: A photoacoustic effect is used in order to measure a flow rate of a flowing medium (M), in particular of natural gas. A light emitter (1) is used to produce in the medium (M) a sound wave (S) which is transmitted by the medium (M) and detected by a sound detector (2). The light emitter (1) is less exposed to the medium (M) than a diaphragm such as used in the ultrasonic method.

Abstract: The present invention discloses a capacitive filling-level sensor, which is suitable in particular for filling-level determination in oil separator tanks. The capacitive sensor includes a measuring probe with at least one sensor electrode. According to the invention, the measuring probe is at least partially sheathed with at least one outer layer of a fluorinated plastic and at least one inner layer of a mica-filled plastic. Important exemplary embodiments concern an outer layer of perfluoroethylene-perfluoropropylene copolymer (FEP), an inner layer of mica-coated glass fiber tape impregnated with epoxy resin and possibly silanized and an incompressible, thermally adapted filling of the measuring-probe pipe with silicone oil and glass spheres or glass polyhedrons and/or an inner rod of AlMgSi-filled epoxy resin. The sheathing is electrically insulating, chemically inert, hydrophobic, oleophobic, waterproof, mechanically robust and easy to produce.