A vibration sensor with a diaphragm that can be excited to a vibration and a drive for setting the diaphragm into vibration and/or for detecting a vibration of the diaphragm, with the drive representing an electromagnetically acting drive and comprising at least one bolt coupled to the diaphragm, a permanent magnet, and a coil, with the drive showing a damper element which is embodied and arranged such that it damps interfering modes to a greater extent than effective modes.

A liquid level sensor is arranged to sense a quantity of a liquid within a reservoir. The sensor includes a plurality of discrete sensing units disposed within the reservoir. Each of the plurality of sensing units has an output, and the output has a first value when the sensing unit is immersed in a liquid and a second value, different from the first value, when the sensing unit is not immersed in a liquid. A signal generator is operably electrically coupled to each of the plurality of sensing units. The signal generator is operable to provide an excitation signal to each of the plurality of sensing units. Each of the plurality of sensing units is operable to provide the output responsive to the excitation signal.

An actuating mechanism includes a main body, an electromagnetic device fixed to the main body, and a swinging rod swingably connected to the main body. A position of connection between the swinging rod and the main body is opposite to an iron core of the electromagnetic device, and an upper end of the swinging rod is opposite to and spaced apart from the electromagnetic device. A permanent magnet is disposed on the upper end of the swinging rod, and a magnetic pole direction of the permanent magnet and a magnetic pole direction of the electromagnetic device cross each other. Since the permanent magnet on the swinging rod is opposite to and spaced apart from the electromagnetic device, the swinging rod is not in contact with the electromagnetic device during working process. This avoids knocking of the swinging rod on other components, and therefore prevents noise, reduces wear.

A powder detection device includes a detection mechanism including an oscillation unit and a vibrated member, a vibrating member, and a detection unit. The oscillation unit outputs a signal having a frequency according to a state of a magnetic flux passing a space facing the oscillation unit. The vibrated member affecting the magnetic flux and disposed inside a container to face the oscillation unit via the container is vibrated by the vibrating member in a direction of facing the oscillation unit. The detection unit acquires frequency information of the signal at predetermined periods, determines presence/absence of an error of the detection mechanism based on error information associating a type of the error with a state of the signal, detects vibration of the vibrated member based on a change in the frequency information, and detects a remaining amount of powder in the container based on the detected vibration.

A method for operating a limit sensor, in which the limit sensor is excited for determining a resonance frequency of a vibration system, the vibration system is excited in a frequency range between a lower frequency limit and an upper frequency limit, and a frequency response is subsequently detected, with the frequency range being divided into a plurality of sections, and in case of an unknown resonance frequency the vibration system is excited sequentially respectively in successive sections, and the frequency response after each section is detected, and in case of a known resonance frequency the vibration system is only excited in the section in which the resonance frequency is found, and then the frequency response is detected.

An apparatus and a method for determining and/or monitoring at least one process variable of a medium in a container, comprising: a mechanically oscillatable unit, a driving/receiving unit for exciting the mechanically oscillatable unit to execute mechanical oscillations by means of an electrical exciting signal and for receiving and transducing mechanical oscillations into an electrical, received signal, an electronics unit, which electronics unit is embodied, to produce the exciting signal starting from the received signal, to set a predeterminable phase shift () between the exciting signal and the received signal, and from the received signal, to determine and/or to monitor the at least one process variable. A phase correction unit is provided, which phase correction unit is at least embodied, to ascertain a phase correction value (.sub.kor) from at least one process parameter dependent, characteristic variable of at least one component of the apparatus, especially the driving/receiving unit, and to set the predeterminable phase shift () in accordance with the phase correction value (.sub.kor).

A method (600) of generating a drive signal for a vibratory sensor (5) is provided. The method (600) includes vibrating a vibratory element (104, 510) configured to provide a vibration signal, receiving the vibration signal from the vibratory element (104, 510) with a receiver circuit (134), generating a drive signal that vibrates the vibratory element (104, 510) with a driver circuit (138) coupled to the receiver circuit (134) and the vibratory element (104, 510), and comparing a phase of the generated drive signal with a phase of the vibration signal.

An apparatus for determining and/or monitoring the viscosity, the density and/or a predetermined filling level, having an excitation/receiving unit which excites a mechanically vibratable unit to vibrate, wherein a control/evaluation unit which is connected to the excitation/receiving unit and has a measuring branch and a checking branch separate from the latter is provided. The checking branch is configured to apply an excitation signal to the excitation/receiving unit, to receive the vibrations of the mechanically vibratable unit and to determine at least a first malfunction and a second different malfunction of the mechanically vibratable unit and/or of the excitation/receiving unit from the received vibrations, wherein the excitation signal of the checking branch has a continuous changing frequency which is described by a frequency/time function and passes through a plurality of modes of the mechanically vibratable unit.

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.

A liquid level sensor is arranged to sense a quantity of a liquid within a reservoir. The sensor includes a plurality of discrete sensing units disposed within the reservoir. Each of the plurality of sensing units has an output, and the output has a first value when the sensing unit is immersed in a liquid and a second value, different from the first value, when the sensing unit is not immersed in a liquid. A signal generator is operably electrically coupled to each of the plurality of sensing units. The signal generator is operable to provide an excitation signal to each of the plurality of sensing units. Each of the plurality of sensing units is operable to provide the output responsive to the excitation signal.