A solid-liquid distribution detection apparatus is adapted to detect a solid-liquid distribution state of a content in a solid-liquid separation column of a freeze concentration device and includes a sound source adapted to emit a sound wave to a column surface of the solid-liquid separation column, a measuring device adapted to measure a resonance waveform on the column surface of the solid-liquid separation column, and an analysis device adapted to analyze the resonance waveform measured by the measuring device and determine the solid-liquid distribution state of the content in the solid-liquid separation column based on an analysis result.

A method for determining and/or monitoring a process variable of a medium using a vibronic sensor includes: exciting a mechanically vibratable unit to vibrate in a first vibration mode via a drive/receiving unit using a first excitation signal; receiving and converting the vibrations of the first vibration mode into a first reception signal; generating the first excitation signal based on the first reception signal; determining the process variable from the first reception signal; exciting the vibratable unit to vibrate in a second vibration mode via the drive/receiving unit via a second excitation signal; receiving and converting the vibrations the second vibration mode into a second reception signal, where the second excitation signal is generated based on the second reception signal; and compensating for an influence of a temperature of the medium on the first reception signal using the second reception signal.

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.

A method for determining a process anomaly in a fluid flow system, the system having a meter with immersed elements immersed in a fluid of a fluid flow is disclosed. The method includes determining, using a data processing circuit (132), a measured density of the fluid in the fluid flow system, determining, using the data processing circuit (132), whether the fluid flow system is experiencing a density anomaly based on a relationship between the measured density and an expected density of the fluid in the fluid flow system, determining, using the data processing circuit (132), a measured phase difference of vibrations of the immersed elements of the meter, determining, using the data processing circuit (132), whether the fluid flow system is experiencing a phase anomaly based on a relationship between the measured phase difference and a target phase difference of the vibrations of the immersed elements in the fluid flow, and identifying an anomaly of the fluid flow system based on the determination of whether there is a density anomaly and the determination of whether there is a phase anomaly.

A method for monitoring condition of a vibronic sensor for determining and/or monitoring at least one process variable of a medium in a containment and having at least one sensor unit having a mechanically oscillatable unit includes: exciting the mechanically oscillatable unit by means of an excitation signal such that mechanical oscillations are executed, and receiving the mechanical oscillations in the form of a received signal, determining a measured value for amplitude and a measured value for frequency of the received signal, comparing the measured values for amplitude and frequency with reference values for amplitude and frequency, and ascertaining a condition indicator from the comparison.

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.

A wound fluid collection system includes a canister adapted to collect bodily fluids from a tissue site. The canister includes an acoustic transducer adapted and positioned to insonify a cavity within the canister, the cavity being defined by a wall of the canister and the bodily fluids collected within the canister. A resonant frequency may be calculated based on a resulting received signal from the insonification. The resonant frequency may indicate a volume of the cavity within the canister. The difference between a known volume of the canister and the calculated volume of the cavity provides the volume of bodily fluid collected in the canister.

The invention provides a method and apparatus for checking the condition of a self-oscillating vibrating fork level switch. The switch includes a test facility that operates when the switch is taken from a closed loop feedback operating mode into an open loop test mode. Amplitudes of the received test signals are subjected to comparison with predetermined thresholds to establish the health of the switch.

The present invention relates to a method for monitoring state of a coil having at least two connection wires, which coil is part of an apparatus for determining at least one process variable of a medium in a containment, as well as relating to an apparatus for executing the method. The method, in such case, includes method steps as follows: ascertaining a desired-value of an ohmic total resistance for the coil and the connection wires, supplying the coil with an electrical excitation signal and receiving an electrical, received signal from the coil by means of the two connection wires, ascertaining an actual-value of the ohmic total resistance based at least on the received signal, and comparing the actual-value with the desired-value and ascertaining a state indicator based on the comparison.

The fluid-level sensor has an acoustic waveguide comprising a flexible metal rod, an electroacoustic transducer coupled to one end of the acoustic waveguide and an acoustic resonator coupled to the other end of the acoustic waveguide. The flexible metal rod has two ends, one cylindrical waveguide coupled via a conical acoustic concentrator to one end of the flexible metal rod, the other cylindrical waveguide coupled via a conical concentrator to the other end of the flexible metal rod. One cylindrical waveguide is coupled to the electroacoustic transducer and the other cylindrical waveguide is coupled to the acoustic resonator. The structure provides for the enhanced functional capabilities of the sensor by using it under the conditions of high temperature, radiation, strong electromagnetic interference, intense vibrations, impacts, and other negative factors. The sensor can be installed, maintained, and repaired without hazard to servicing personnel.