A field device used in process and/or automation engineering for monitoring at least one chemical or physical process variable of a medium in a component carrying a medium at least partially and temporarily and comprising at least an electronic unit and a sensor unit. At least one portion of at least one component of the sensor unit is in contact with the medium at least temporarily. The at least one portion of the component in contact with the medium is provided with a chemically resistant multilayered coating consisting of at least two layers, wherein a first layer is made of a material consisting of a densely packed atomic arrangement which provides a protection against corrosion by said medium, and a second layer consisting of a chemically resistant plastic material is arranged around the first layer and protects the first layer against outer damage and corrosion.

A redundant level measuring system comprises comprising a chamber for fluidic coupling to a process vessel whereby material level in the vessel equalizes with material level in the chamber. A float including a magnet in the chamber interior space rises and falls with material level in the chamber. The float comprises an inner cylindrical wall defining an elongate through opening. A magnet actuated visual indicator is mounted to the chamber for indicating level of the magnet in the chamber. A level measurement instrument includes a measurement circuit and a coaxial probe having an inner rod and a coaxial outer tube. The probe defines a transmission line and the coaxial outer tube has a through opening so that material level in the chamber equalizes with material level in the coaxial outer tube. The instrument is mounted atop the chamber with the probe directed downwardly to the chamber interior space and extending through the float through opening. The measurement circuit generates and receives a frequency signal on the transmission line, the measurement circuit measuring level of the material in the coaxial outer tube.

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 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 invention is a fill-level measuring device having the following features: a housing, a membrane, a first drive unit have a first bolt, the bolt being coupled to the membrane, a second drive unit having a second bolt, the second bolt being operatively connected to the membrane and being connected to the housing at an end of the second bolt facing the membrane by means of an intermediate bottom, and the first drive unit and the second drive unit are mechanically connected to each other in series.

Disclosed is an apparatus for determining a process variable of a medium in a containment, comprising a first oscillatory element and a second oscillatory element, a first driving/receiving unit and a second driving/receiving unit, and an electronics, wherein the first driving/receiving unit is embodied to excite the first oscillatory element by means of a first electrical excitation signal to execute mechanical oscillations, and to receive the mechanical oscillations of the first oscillatory element and to convert such into a first electrical, received signal, wherein the second driving/receiving unit is embodied to excite the second oscillatory element by means of a second electrical excitation signal to execute mechanical oscillations, and to receive the mechanical oscillations of the second oscillatory element and to convert such into a second electrical, received signal, and wherein the electronics is embodied to determine the process variable from the first received signal and/or the second received signal.

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.

Devices and methods for proximity detection based on sound are provided. According to an embodiment, an acoustic probe includes a sound generator and an acoustic sensor, and at least one of the sound generator or the acoustic sensor is disposed within the dispense chamber portion. According to an embodiment, the liquid dispenser includes a sound generator and an acoustic sensor, and further includes one or more side conduits, where at least one of the sound generator or the acoustic sensor is disposed within a cavity of a respective one of the one or more side conduits, wherein the cavity and a connector of each of the one or more side conduits are free from resonance within a frequency range of the sound sensed by the acoustic sensor.

Disclosed is a measuring device and a method for measuring a dielectric value of a fill substance. The measuring device includes a signal production unit for driving a transmitting unit to transmit a radar signal toward the fill substance; a receiving unit for receiving of the radar signal; and an evaluation unit to ascertain an amplitude of the received signal, a phase shift, and/or a signal travel time of the radar signal. Based on the signal travel time, the phase shift, and/or the ascertained amplitude, the dielectric value can be determined. The transmitting unit and the receiving unit comprise at least two radiating elements arranged relative to one another in a corresponding number of rows. Because of a per row increasing phase delay, the measuring range over which the dielectric value can be determined is increased.

A vibrating fork liquid level switch includes a vibrating fork assembly arranged to vibrate at a first frequency when in contact with a process fluid and at a second frequency when in contact with air. A drive circuit connected to the vibrating fork assembly is configured to drive the vibrating fork assembly into oscillation. Sense circuitry senses an oscillation frequency of the vibrating fork assembly. Output circuitry provides a first output when the sensed oscillation is at the first frequency and a second output when the sensed oscillation is at the second frequency. Control circuitry controls power applied to the vibrating fork assembly by the drive circuit between a first and a second power level. Verification circuitry verifies the oscillation frequency of the vibrating fork assembly when power applied to the vibrating fork assembly by the drive circuitry is changed.