摘要:
A measuring device having at least one corrosion resistant, process-facing surface, wherein at least one joint between a component of an electrically conductive material and a component of an electrically insulating material is sealed with a sealing structure, and wherein the process-facing surface is provided with a coating in such a manner that at least the sealing structure, a transitional region between the conductive component and the sealing structure and a transitional region between the insulating component and the sealing structure are covered by the coating.
摘要:
The invention relates to an apparatus for monitoring a field device for determining and/or monitoring a physical and/or chemical process parameter of a process medium with a first sealing stage facing toward the process and at least one housing with a predetermined interior volume. The housing is located on the side of the first sealing stage facing away from the process, wherein energy is transferable through the first sealing stage 4 in the direction of the process medium. This energy interacts with the process medium, wherein at least one detector unit is provided in the housing, which unit monitors at least one condition parameter of the interior volume of the housing. A control/evaluation device determines, on the basis of the energy interacting with the process medium, the physical and/or chemical process parameter, and wherein the control/evaluation unit and/or another monitoring unit recognizes and/or seals off and/or issues an alarm, on the basis of the monitored condition parameter in the interior volume of the housing, as soon as the monitored condition parameter in the interior volume of the housing a predetermined limit value.
摘要:
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.
摘要:
A fill-level measuring device with a membrane, which is placed in such a manner on one of the two end region of a tubular housing that it seals the housing on such end region. An oscillatable unit is placed on the side of the membrane facing away from the housing, with a driver/receiver unit, which is composed of a plurality of piezoelectric elements arranged in a stack. The driver/receiver unit is placed via a pressure screw unit in such a manner in the housing that it oscillates in the direction of the longitudinal axis of the housing between the membrane and the pressure screw unit. The driver/receiver unit excites the oscillatable unit via the membrane to execute oscillations, with a control/evaluation unit, which evaluates amplitude, frequency and/or phase of the oscillations of the oscillatable unit and with a temperature sensor for determining temperature of the medium. The temperature sensor is integrated in a fill-level measuring device element, which is in thermal contact with the medium via the membrane or the housing, wherein the element is so selected that the oscillatable unit oscillates unimpaired by the temperature sensor.
摘要:
An apparatus for determining and/or monitoring at least one process variable of a medium in a container which comprises a mechanically oscillatable structure, which has at least one oscillation characteristic dependent on the process variable, an electromechanical transducer having at least one piezoelectric element, which excites the structure, by means of an excitation signal supplied to the transducer, to execute mechanical oscillations, and which converts the resulting oscillations of the structure into a received signal, which corresponds to a superpositioning of the excitation signal and a wanted signal representing the oscillation. A reference element in parallel with the transducer and supplied with the excitation signal, via which a reference signal independent of the oscillation and corresponding to the excitation signal is tapped, and an electronics, which, based on the received signal and the reference signal, extracts the wanted signal, and, based on the wanted signal, determines and/or monitors the process variable, wherein, for automatic measuring of temperature of the transducer, the electronics includes a temperature measuring device, which supplies the transducer and the reference element, in temperature measurement operation, with an auxiliary signal, whose frequency lies outside a frequency range predetermined by a resonant frequency of the oscillatory structure, and, based on the wanted signal extracted in temperature measurement operation, determines a temperature of the transducer.
摘要:
A method and an apparatus for determining at least one flow characteristic of an essentially laminarly flowing, gaseous or liquid medium in a pipeline. Distinguishing features include: that at least one modulation element introduced into, or placed in, the pipeline produces, at least for the case, in which the medium is flowing with a velocity different from zero, a change in density of the medium, at least at times, in the vicinity of the modulation element; that at least one mechanically oscillatable unit introduced into, or placed in, the pipeline and spaced from the modulation element is excited to resonant oscillations; that mechanical oscillations are received by the mechanically oscillatable unit and converted into an electrical, received signal, wherein the received signal is sensitive to the density change; and that the at least one flow characteristic of the medium is determined from the reaction of the received signal of the mechanically oscillatable unit to the density change.
摘要:
A multivariable sensor for determining and/or monitoring a predetermined fill level and density and/or viscosity of a liquid in a container. The sensor comprises a measuring tube provided in the container. The measuring tube has at least a first oscillatable segment and a second oscillatable segment, wherein the oscillatable segments have a cross sectional area deviating from a circularly round shape and at least one straight side, wherein on an inner wall of the oscillatable segments, driver/receiving units are placed, which cause the oscillatable segments to execute resonant oscillations. At least one control/evaluation unit is provided, which evaluates frequency and/or phase and/or amplitude of the oscillations and determines therefrom reaching of the predetermined fill level and density and/or viscosity of the liquid.
摘要:
An apparatus for determining and/or monitoring at least one physical or chemical, process variable of a medium and includes at least one mechanically oscillatable unit and at least one driving/receiving unit. The mechanically oscillatable unit includes a tube and an internal oscillator. The tube is connected to a securement unit with an end turned away from the process and the end of the tube turned toward the process is embodied as a free end. The tube surrounds the internal oscillator and the internal oscillator is secured to the end of the tube turned toward the process with an end turned toward the process. The driving/receiving unit excites the mechanically oscillatable unit to oscillate, respectively it receives the oscillations of the mechanically oscillatable unit. The internal oscillator has at least one groove/neck, which determines at least the oscillation frequency of the mechanically oscillatable unit.
摘要:
The measurement transducer includes at least two oscillatably held transducer tubes vibrating, at least at times, during operation, of which at least one transducer tube serving to convey at least a volume portion of a medium to be measured, communicates with a pipeline; as well as at least one transducer element for converting electrical energy into mechanical and/or vice versa. The two transducer tubes are mechanically coupled together by means of at least one, inlet-side, coupling element and by means of at least one, outlet-side, coupling element in such a manner that both the inlet-side coupling element, as well as also the outlet-side coupling element, are subjected during operation repeatedly to deformations which correspond to vibrations of at least one of the two transducer tubes for converting electrical energy into mechanical, oscillatory energy and/or vice versa. The transducer element, especially a transducer element formed by means of a piezoelectric, deformation body, and at least one of the coupling elements, are, at least mediately, mechanically coupled together in such a manner that the transducer element executes, at least in part, oscillatory movements, which correspond with the repeated deformations at least of this coupling element.
摘要:
An electromechanical transducer with at least one piezoelectric element with a first surface on which a first electrode is applied, and at least one contact flag, through which the piezoelectric element is electrically connected. The electrical connection of the piezoelectric element is of very high contact reliability, in that the contact flag directly contacts the first electrode and exhibits at least one depression, into which an adhesive is placed, by which the contact flag is connected with the electrode.