Abstract: In a device for measuring the filling level, thermoelements (20) are used which are disposed on a sheet-shaped support (25). The thermoelements (20) consist of two different materials and are disposed in two rows (71, 72) placed side by side. Two adjacent thermoelements (20) of said rows (71, 72) have a common junction point (23) that is heated. Both rows (71, 72) of thermoelements also have two additional junction points that are cold. A first group of thermoelements (20) is disposed with their supports (25) in the interior of the container and operate as measuring detectors. A second group of thermoelements (20) serves as reference sensors since they regulate the heat flow impinging upon the junctions points (23) relative to a defined reference voltage.

Abstract: A system for scanning vibrations of a mass and for converting the mechanical vibrations into corresponding electrical signals is disclosed. The system includes a source of a scanning radiation beam, preferably of a light beam, which has a larger transverse cross section than the vibrating mass. The umbra behind the mass and the surrounding illuminated area are collected by a focussing lens and projected onto an optoelectric converter. The collecting surface and/or the active light receiving surface of the converter have an outline which is variable in the direction of displacement of the vibrating mass so that the illuminated area varies in size during the vibration of the mass.