A device for determining and/or monitoring at least one process variable of a medium in a container includes four, rod-shaped elements arranged on a membrane, three piezoelectric elements and an electronics system, wherein one first and one second rod-shaped element are arranged and configured such that they form a mechanically vibratable unit, wherein the device is configured to excite the vibratable unit via an excitation signal to create mechanical oscillations, to receive the mechanical oscillations of the vibratable unit, to convert them into a first received signal, to transmit a transmitted signal, and to receive a second received signal, and wherein the electronics system is configured to determine the at least one process variable based on the first and/or second received signal.

A method for the measurement of a physical parameter of a liquid by means of a sensor having at least one measuring tube for conducting the liquid, wherein the measuring tube can be excited to vibrate in at least one flexural vibration mode, comprises: determining at least one current value of a vibration parameter of the flexural vibration mode; determining a measurement value of the physical parameter according to the current value of the vibration parameter, wherein the measurement value is compensated in respect of the resonator effect according to a current value for the natural frequency of the flexural vibration mode and according to the sound velocity of the liquid conducted in the measuring tube, wherein the value for the sound velocity is provided independently of the vibrations of the measuring tube.

The invention provides a method of driving a vibrating sensor in which the drive signal is combined with an amplitude modulated high frequency carrier. The signal is demodulated at a position adjacent to the component to be driven. This method may be applied to reducing cross-talk between drive and pick-up wire pairs and also to passing both drive and pickup signals, and two drive signals, down the same wire pair.

A flow sensor includes a flow tube in a form of a tube and a support cast around the flow tube. The support clamps the flow tube and the flow tube extends through the support. The flow sensor is formed by placing the flow tube in a tube cavity of a casting mold and pouring or injecting a liquid resin into a support cavity of the casting mold. The support is formed around the flow tube from solidifying the liquid resin in the support cavity of the casting mold. A temperature of the casting mold during formation of the support does not exceed a threshold temperature to avoid deformation of the flow tube. The flow sensor can also include at least one memory chip that stores calibration information associated with the flow sensor and connectors that allows a controller to read the calibration information from the memory chip.

A densitometer in the present disclosure comprises a piston attached to an end of a tube of the densitometer to reduce pressure dependence of density estimates of a sample fluid. The densitometer measures sample fluid density by vibrating the tube containing sample fluid and measuring the resonant frequency of the tube, then estimating the sample fluid density based on this resonant frequency. The piston is designed with a predetermined diameter that converts pressure inside the tube to tension in the tube. This tension produces an opposite effect on the resonant frequency of the tube to that caused by the fluid pressure itself and thereby reduces pressure dependence of the sample fluid density estimates.

A device and a method for determining and/or monitoring at least one process variable of a medium include a sensor unit having a mechanically oscillatable unit, at least a first piezoelectric element, a conductivity/capacitance detecting unit for determining and/or monitoring a conductivity and/or capacitance of the medium and an electronics unit. The device is embodied to excite the mechanically oscillatable unit by means of an excitation signal such that mechanical oscillations are executed, to receive the mechanical oscillations of the oscillatable unit, to convert them into a first received signal, to transmit a transmitted signal, and to receive a second received signal. The electronics unit is embodied, based on the first and/or second received signal, to determine the at least one process variable of the medium.

The present disclosure relates to a method for calculating a quality pertaining to at least one measuring tube of a Coriolis measuring device for measuring a density or a mass flow of a medium flowing through the measuring tube, wherein a determination regarding a state of the measuring tube can be made by determining various vibration properties.

The present disclosure relates to a density meter for slurry which is transported through a pipe, the density meter may include a frame; a pipe part; flexible pipe couplings arranged between the frame and either end of the pipe part for coupling the pipe part to the frame and to a feed pipe and a discharge pipe; a first accelerometer arranged on the pipe part for measuring the accelerations of the pipe part; an actuator arranged between the pipe part and the frame for imparting force on the pipe; a controller for controlling the actuator; and a computing means having a mathematical model to ultimately calculate the density of the slurry in the pipe part.

A device and a method for measuring and/or monitoring at least one process variable of a medium is provided. The device comprises a sensor unit with a mechanically vibrating unit, at least one reflection unit, a piezoelectric element which is attached to the membrane, and an electronic. The device is designed to excite the mechanically vibrating unit to mechanical vibrations using an excitation signal, to receive the mechanical vibrations of the vibrating unit and convert them into a first reception signal, to emit a transmission signal, and to receive a second reception signal. The electronic unit is designed to determine the at least one process variable of the medium based on the first and/or second reception signal.

A densitometer in the present disclosure comprises a measurement module that is calibrated to estimate sample fluid density with high accuracy and minimized sensitivity to temperature of tube and clamp components in the densitometer. The densitometer measures sample fluid density by vibrating the sample fluid and measuring the resonant frequency of the sample fluid, then estimating the sample fluid density based on this resonant frequency. The measurement module is calibrated specific to dissimilar tube and clamp materials. The tube and the clamp of the densitometer have materials are chosen to be cost-effective based on the specifications of the densitometer system and to have coefficients of thermal expansion (CTEs) which reduce temperature dependence of the resonant frequency of the sample fluid inside of the densitometer.