Vibronic sensor and method of operation for monitoring the density and/or the viscosity of a medium in a container, comprising a mechanically oscillatable unit, a driving/receiving unit and an electronics unit, wherein the driving/receiving unit is embodied, using an electrical exciter signal, to excite the mechanically oscillatable unit to execute mechanical oscillations, and to receive the mechanical oscillations and to convert them into an electrical, received signal, wherein the electronics unit is embodied to produce the exciter signal such that a predeterminable phase shift is present between the exciter signal and received signal, wherein the electronics unit is embodied to set a first predeterminable phase shift and a second predeterminable phase shift, and to ascertain a first frequency and a second frequency corresponding to the predeterminable phase shifts, and to determine from the two frequencies the density and/or the viscosity of the medium using a first and/or second analytical formula.

The present disclosure relates to a field device of automation technology, comprising a housing and a sensor unit sensitive for a process variable of a medium. The housing has a passageway to accommodate the sensor unit and the sensor unit protrudes from the housing through a terminal opening of the passageway. A clamping angle and a screw are introduced into the housing in a region of the housing adjoining the opening of the passageway. By means of the screw the clamping angle is shiftable in the housing a predeterminable distance in the direction of the sensor unit, and the clamping angle shifted in the direction of the sensor unit is embodied to press with a first clamping angle section of the clamping angle radially on a clamping region of the sensor unit arranged in the housing and facing the opening of the passageway.

An apparatus for determining and/or monitoring at least one process variable of a medium in a container, comprising at least an oscillatable unit having at least one membrane, and at least one oscillatory element, a driving/receiving unit embodied to excite the mechanically oscillatable unit by means of an electrical, exciter signal of adjustable excitation frequency to execute oscillations in an oscillation mode corresponding to the excitation frequency and to receive mechanical oscillations from the oscillatable unit and to convert such into an electrical received signal, and an electronics unit embodied, to produce the exciter signal, and to ascertain from the received signal the at least one process variable. The membrane is connected with the driving/receiving unit. The oscillatory element has the shape of an oscillatory rod, on which a paddle is terminally formed, and the oscillatory element is secured on the membrane in an end region remote from the paddle. Mass distribution, stiffness and/or geometry of the oscillatable unit is/are selected in such a manner that at least one of the oscillation modes of the oscillatable unit higher in reference to the oscillation mode corresponding to the excitation frequency lies in the range between two neighboring whole-numbered multiples of the excitation frequency.

The present disclosure relates to a method for determining a process variable of a medium by means of a vibronic sensor. In a first operating mode, an oscillatable unit is excited by a first electrical excitation signal, such that it executes mechanical oscillations, and the mechanical oscillations of the mechanically oscillatable unit are received and converted into a first electrical, received signal having a first frequency. Furthermore, the first received signal is evaluated relative to the process variable. In a second operating mode, mechanical oscillations of the oscillatable unit are received and converted into a second electrical, received signal, wherein a second frequency of the second electrical, received signal is ascertained, and wherein the second frequency is associated with a first disturbing influence for the vibronic sensor. Furthermore, the present disclosure relates to an apparatus, which is suitable for performing a method of the present disclosure.

An ultrasonic sensor for detecting the presence or absence of an aerated fluid includes a probe having a first solid portion and a second hollow portion. The probe has a closed end at the hollow portion. The solid portion and the hollow portion define an interface therebetween. A transducer element is mounted to the probe at about the solid portion. The transducer element is configured to transmit an ultrasonic signal through the solid portion into the hollow portion and to receive reflections of the ultrasonic signal to determine the presence or absence of a fluid and/or an aerated fluid.

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.

The a vibration sensor comprising a membrane that can be stimulated so as to oscillate by means of a piezoelectric drive, and a mechanical oscillator arranged on the membrane, at least one piezoelectric element of the drive comprising at least one first electrical contact structure on an upper side of the piezoelectric element and at least one second electrical contact structure on a lower side of the piezoelectric element, such that the at least one piezoelectric element is designed so that an active area of the piezoelectric element corresponds to an area of a mechanical deformation of the unidirectional curvature of the membrane, during a pre-defined eigenmode of the mechanical oscillator.

The invention relates to a compensation device for the compensation of a phase shift caused a component of an electronic system unit of a vibronic sensor. The compensation device includes a bridging unit for the electrical bridging of at least the electromechanical converter; a signal generator for generating a test excitation signal; a phase detection unit for determining the phase shift between the test excitation signal and a test receive signal that passes through the bridging unit and the component of the electronic system unit; and a computer unit which determines a phase compensation instruction from the first phase shift.

The present invention relates to a vibronic sensor for determining a process variable of a medium in a containment, comprising a mechanically oscillatable unit, a driving/receiving unit and an electronics unit having an adaptive filter. The present invention relates also to a method for operating the sensor. The electronics unit is embodied alternately to execute a first operating mode and a second operating mode. The driving/receiving unit is embodied during the first operating mode to excite the oscillatable unit using an electrical excitation signal. During the second operating mode, the exciting of the oscillatable unit is interrupted and the oscillations of the oscillatable unit are received and transduced into an electrical, received signal. At least one filter characteristic of the adaptive filter is set such that a predeterminable phase shift is present between the excitation signal and the received signal, and the process variable is determined from the received signal.

A field device comprising first and second tines; first and second rods coupled to the first and second tines; a coil arrangement fixed to the first rod; a magnet fixed to the second rod, opposite the coil arrangement; excitation circuitry coupled to the coil arrangement and controllable to provide a time-varying current to the coil arrangement, resulting in vibration of the first tine in relation to the second tine; sensing circuitry coupled to the coil arrangement and configured to provide a sensing signal indicative of a change in at least one property of the vibration of the first tine in relation to the second tine; and measurement control circuitry coupled to the excitation circuitry and the sensing circuitry for controlling operation of the excitation circuitry.