Abstract: A level switch detects the fill level of a medium in a container and transmits a switch signal corresponding to the detected level. The level switch incorporates a signal generator for generating an electromagnetic signal, a measuring circuit, and a reference circuit into which the electromagnetic signal can be fed. The measuring circuit is so configured and positioned that the signal fed into the measuring circuit changes as a function of whether or not the measuring circuit is surrounded by the medium, while the reference circuit is so configured and positioned that the signal fed into the reference circuit remains unaffected by the fill level of the medium. A tap at a specific point on the measuring circuit collects the measuring voltage, a tap at a specific point on the reference circuit collects a reference voltage, and a voltage comparator compares the measuring voltage with the reference voltage and emits a comparison-derived switch signal.

Abstract: A method for measuring the fill level of a medium in a container by applying the radar principle, whereby a measuring signal is generated and transmitted in the direction of the medium. A retroreflected portion of the measuring signal is captured and the fill level is determined as a function of the runtime of the measuring signal. The measuring signal is transmitted into multiple mutually different regions and the retroreflected portions of the measuring signal is received at multiple receiving points. In this fashion, it is possible to at least approximate the surface structure of the medium in the container.

Abstract: A process for measurement of the level of a medium in a container based on the radar principle in which a measurement signal is generated and emitted in the direction of the medium, the portion of the measurement signal which has been reflected back is detected and the level determined from the propagation time of the measurement signal. The portion of the measurement signal which has been reflected back is evaluated in a phase-sensitive manner in order to assign the respective level corresponding to the propagation time of the measurement signal to a specific direction of space. Thus, the level is determined even under difficult conditions, such as when structures or devices are present in the container or when loose bulk materials are present in loose bulk cones.

Abstract: A radar fill-level sensing device has a high-frequency unit that serves to generate and process radar signals of a predefined frequency and wavelength, an antenna for transmitting and/or receiving the radar signals, as well as circuitry, provided on a circuit board. That circuitry includes a microstrip circuit for connecting the high-frequency unit to the antenna, that microstrip circuit featuring a ground conductor. The ground conductor encompasses a first segment, a radial stub and a second segment, the length of the first segment corresponding essentially to one quarter of the predefined wavelength. The radial stub is positioned at the end of the first segment, the second segment connects to the end of the first segment and to the radial stub, and the second segment is grounded. Based on this design, a radar fill-level sensing device is obtained that can easily and reproducibly be implemented within the requirements of “intrinsically safe” ignition protection.

Abstract: A sampling circuit for sequential sampling of a broadband periodic input signal having a field effect transistor as a nonlinear component to which a pulsed-shaped sampling signal is supplied, by which sampling is activated so that an output signal is produced. In this way, a sampling circuit is attained which is economical, technically durable and which can be used in a versatile and simple manner.

Abstract: A fill-level detector operating by the radar principle gauges the fill-level of the lower of two substances layered one atop the other in a container. The detector incorporates first and second essentially straight, parallel electrical conductors having a signal generator and a transducer mounted to the upper ends of the conductors with the lower ends of the conductors protruding into the lower substance. The generator delivers a signal to the first conductor which signal is conducted into the lower substance with a portion of that signal being reflected at the interface of the two substances which signal portion is captured by the transducer. The detector is able to determine to fill level of the lower substance even when the upper substance displays a high dielectric constant.

Abstract: Illustrated and described is an ultrasonic flowmeter for flowing media, that operates according to the transit time method, with a measuring tube and at least one transmitting and/or receiving head, in connection with which the transmitting and/or receiving head has a housing and an ultrasonic transducer with which ultrasonic signals can be emitted into the flowing medium and ultrasonic signals can be received from the flowing medium. The ultrasonic flowmeter for flowing media is characterized in that a damping device with at least one damping element is arranged around the sides of the housing of the transmitting and/or receiving head and at least partly adjacent to it, and the damping device is provided in a recess of the measuring tube.