The present disclosure relates to an apparatus for determining and/or monitoring a process variable of a medium in a containment, including an oscillatable unit with a membrane, three rods secured to the membrane and extending perpendicularly to a base area of the membrane, a housing, wherein the rods extend into the housing a driving/receiving unit disposed at an end region of the rods and configured to excite the oscillatable unit and transduce mechanical oscillations into a received signal, and an electronics unit configured to produce an exciter signal from the received signal and to ascertain the process variable at least from the received signal. At least one of the rods is secured to the membrane at a site on the base area where the second derivative of the deflection of the membrane from a rest position as a function of the site on the base area is essentially zero.

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 filling level monitoring device for monitoring a filling level of a fluid in a container includes exciter(s), sensor(s), a signal source connected to the exciter(s), a processor, at least one spatial orientation and acceleration sensor, and a filling level indicator. The device uses the signal source and the exciter(s) to couple vibrational loads having multiple frequency components into the container. Sensors measure vibrations in the container after the exciters transmit the vibrational loads into the container. The processor performs spectral analysis of the input signal and of vibration signals from the sensors, comparing these respective spectral functions to extract resonance frequencies of the container, which are based on the spatial orientation of the container. The filling level indicator calculates a current filling level of the container from the extracted resonance frequencies and a spatial orientation signal from a spatial orientation sensor by correlating the collected data with reference data.

The present disclosure includes an electromechanical transducer unit for a field device of automation technology including a membrane having a base area and displaceable to execute mechanical oscillations, three rods secured to the membrane perpendicular to the base area, a housing, wherein the rods extend into the housing, three magnets, each secured to one of the rods opposite the membrane, and a coil having a core and secured within the housing adjacent the magnets, the coil embodied to produce a magnetic field that causes the rods to execute mechanical oscillations. The rods are secured to the membrane such that oscillations of the membrane result from the oscillations of the rods. At least one of the rods is secured to the base area where the second derivative of the deflection of the membrane from a rest position as a function of the site on the base area is essentially zero.

A liquid surface sensor includes a hollow member having a first opening end and a second opening end, and a sensor unit provided so as to close the first opening end of the hollow member. The sensor unit includes a vibration plate, and a piezoelectric element which is provided on the vibration plate and is formed by laminating a first electrode film, a piezoelectric film, and a second electrode film in a thickness direction of the vibration plate.

A system for determining and/or monitoring a process variable of a medium in a container, comprising a sensor module with an oscillatable unit, which is arranged in such a manner in the container that the oscillatable unit extends to a defined immersion depth in the medium, or that the oscillatable unit is placed at the height of the predetermined fill level, a tubular extension and/or a temperature reduction unit of a defined length, a contacting module and an electronics module, composed of an exciter/receiving unit, which excites the oscillatable unit to execute oscillations and receives the oscillations of the oscillatable unit. Two electrical coupling paths are associated with the electronics module, and a control/evaluation unit, which based on at least one oscillation variable of the oscillations or based on a change of an oscillation variable of the oscillations, provides information concerning the process variable or the reaching of the predetermined fill level. The sensor module and the electronics module are either electrically connected directly with one another, wherein one of the two electrical coupling paths is activated, or wherein the sensor module and the electronics module are indirectly electrically connected with one another via the contacting module, and wherein both coupling paths are activated.

A method for determining a height (h.sub.s) of a settled bed in a mixture in a loading space (1). The mixture consists of a settled bed (5) and a mixture soup (3) which is located above the settled bed (5). The method includes: a) providing an elongated resonance member (10) in the loading space (1) which extends in a substantial vertical direction, b) measuring a resonance frequency (f.sub.o) of the resonance member (10), c) computing a height (h.sub.s) of the settled bed (5), Action b) includes determining an indication of or imposing the tensile force (F.sub.s) acting in the longitudinal direction of the resonance member (10) and c) includes computing a height (h.sub.s) of the settled bed (5) based on the measured resonance frequency (f.sub.o) and the determined indication of the tensile force or the imposed tensile force.

Apparatus for determining and/or monitoring at least one process variable of a medium in a container. The apparatus includes at least one mechanically oscillatable unit, and at least one driving/receiving unit, which excites the mechanically oscillatable unit to execute mechanical oscillations, and which receives the mechanical oscillations of the mechanically oscillatable unit. The mechanically oscillatable unit has at least one membrane, or diaphragm. The membrane, or diaphragm, is connected with a housing. The driving/receiving unit is arranged between the membrane and a holding portion, and the holding portion is secured to the housing. The invention holding portion is embodied in such a manner and secured to the housing in such a manner, that a radial force, which acts essentially in the direction of the normals of the housing, produces a force component and/or a moment, which acts essentially in the direction of a normal of the holding portion.

A bottle having a water volume measuring function comprises a bottle-lid, a bottle-body, and a measure module disposed in the bottle-lid which comprises at least a micro controller unit, a memory unit and a sound wave transceiver unit. The memory unit stores a lookup table with corresponding relationships between a plurality of frequencies and remained water volumes in the bottle-body. The sound wave transceiver unit emits sound waves with sweeping frequencies towards the bottle-body and receives reflected waves. The micro controller unit determines if any frequency of the sound waves is an air-resonance frequency according to the energy level of each of the reflected waves. When a sound wave frequency is determined as an air-resonance frequency, the micro controller unit obtains the corresponding remained water volume by checking with the air-resonance frequency in the lookup table and users can view the remained water volume without opening the bottle-lid.

Audio level indicators are known which comprise moving needles, or an array of lights, or an illuminated bar. However, the way in which they provide information is fixed. A programmable audio level indicator for use with a mixing desk is provided which comprises a first light source arranged to emit a coloured light, in response to an audio signal received from a connected audio source, to indicate the audio level of that received signal, the indicator arranged to vary the colour and intensity of the light emitted as the audio level changes, wherein the indicator is configured such that the audio levels at which the colour changes are selectable, the indicator further configured such that the colour emitted to indicate an audio level, or range of audio levels, is also selectable.