An Apparatus for determining and/or monitoring at least one process variable of a medium in a container, comprising: a mechanically oscillatable unit a driving/receiving unit for exciting the mechanically oscillatable unit to execute mechanical oscillations by means of an electrical, exciting signal and for receiving and transducing the mechanical oscillations into an electrical, received signal a control unit, which is embodied to produce the exciter signal starting from the received signal and to set a predeterminable phase shift between the exciter signal and the received signal, an electromagnetically oscillatable unit, an active element for producing and/or maintaining electromagnetic oscillations in the electromagnetically oscillatable unit, which active element forms together with the electromagnetically oscillatable unit an oscillator, a coupling unit, which is embodied to tap an output signal from the active element, and an evaluation unit, which evaluation unit is embodied to determine the at least one process variable from the received signal and/or from the output signal.

A device for providing a gas and temperature compensated acoustic measurement of the level of a liquid surface, including a transmitter, a receiver, and a waveguide for guiding acoustic signals. The waveguide includes a reference portion extending from a first end to a reference element, and a measurement portion extending from the reference element towards the end. The device further includes a channel extending from at least one inlet in said reference portion to at least one outlet in said measurement portion, the channel being separated from the waveguide so as to provide a fluid flow independent of the waveguide, and a gas-pump arranged to create a gas flow in said channel from said at least one inlet to said at least one outlet.

The invention relates to a vibration sensor with a housing and a mechanical oscillator, with a first tine and a second tine arranged thereon, and a drive for exciting the mechanical oscillator, wherein the drive is fixed relative to the mechanical oscillator by means of a yoke, wherein the yoke defines at least one yoke cavity, wherein a shoulder of at least one tine defines a tine cavity, wherein the yoke cavity and the tine cavity are aligned with one another, and wherein a balancing element is moveably arranged in the yoke cavity, so that it can be arranged at least partially in the tine cavity. The invention further relates to a method for comparing the vibration properties of two tines of a vibration sensor.

A system includes a controller for monitoring a fill level of a container. The controller is configured to receive first vibrational response data relating to a vibrational response of the container in a first state, receive second vibrational response data relating to a vibrational response of the container in a second state, and use the first vibrational response data and the second vibrational response data to identify a change in fill level of the container between the first state and the second state.

The invention provides a field device configured to be fitted through a single mounting aperture in a vessel. The device preferably includes a vibrating fork and a temperature sensor, the signals from which are processed within the device to provide an output indicative of whether a property of a medium in contact with the device is above or below a threshold. This output may be communicated wirelessly to a remote location. Other features are described.

An apparatus for determining and/or monitoring at least one process variable of a medium in a container, comprising: a mechanically oscillatable unit; an electrodynamic transducer unit for exciting the oscillatable unit by means of an exciter signal to execute mechanical oscillations and for receiving the mechanical oscillations of the oscillatable unit and transducing them into an electrical, received signal; and an electronics unit, which at least determines and/or monitors the process variable based on the received signal. The invention is distinguished by features including that the electrodynamic transducer unit has exactly one coil, which serves both as a drive element as well as also a receiving element.

Provided is a fuel tank for a vehicle in which a fuel measure bar provided in a vertical direction in a fuel storing body in which a fuel combusted in an engine is stored and capable of measuring a fuel amount using an ultrasonic wave includes a first fuel measure bar fixed to a bottom surface of the fuel storing body and a second fuel measuring bar easily coupled to the first fuel measuring bar to easily enter the fuel storing body and exit from the fuel storing body.

A device for determining a predetermined fill level of a liquid in a container, with a sensor unit, comprising a unit capable of oscillating mechanically, a transmitter unit, and a receiver unit, which is electrically and mechanically coupled to the transmitter unit, and which transduces the oscillation of the unit capable of oscillating into an electrical receiving signal. An electronic unit, comprising a regulating unit, which regulates a phase difference that exists between the electrical transmission signal and electrical receiving signal to a determined value at which the unit capable of oscillating conducts oscillations at a resonant frequency, and which forms an oscillation circuit with the transmitter unit, receiving unit and the unit capable of oscillating. The electronic unit comprises a compensation path with a compensation unit, which for compensating additional signal components in the receiving signal, which results from the mechanical and/or electrical coupling between transmitter unit and receiver unit, at least intermittently produces a compensation signal from the transmission signal and supplies this compensation signal to the receiving signal. The compensation unit produces the compensation signal in a way such that the compensation signal is opposite to the additional signal components in the receiving signal.

A liquid detecting apparatus includes an ultrasonic sensor that transmits and receives an ultrasonic wave, and includes a piezoelectric layer which is formed of a thin film and an ultrasonic element which is provided with a first electrode and a second electrode to interpose the piezoelectric layer between the first electrode and the second electrode, on a diaphragm which is disposed on a substrate having a cavity, and a flow path that forms the same liquid level as a liquid level of a liquid which is stored in a container, in which an acoustic matching layer and a detection surface of a surface of a lens, which are disposed on a side of the ultrasonic sensor that transmits and receives the ultrasonic wave, are disposed to be in contact with the liquid within the flow path.

A method and a system for evaluating a content of a bin, the method may include: transmitting by multiple acoustic transceiver arrays, a plurality of acoustics pulses in an at least partially overlapping manner towards an expected location of the content to generate an acoustic interference pattern that comprises multiple fringes; detecting by an acoustic transceiver array a first fringe of the acoustic interference pattern and providing a fringe detection signal; and processing the first fringe detection signal to assist in a provision of a first estimate related to the content. A distance between a pair of acoustic transceiver arrays is at least ten times a distance between transducers of a same acoustic transceiver array.