Abstract: The acoustic waveguide has a flexible metal rod with a cylindrical waveguide rigidly attached to each end of the same through a conical acoustic concentrator. One cylindrical waveguide is capable of being attached to an electroacoustic transducer and the other cylindrical waveguide is capable of being attached to an acoustic oscillation receiver. The structure provides for the enhanced functional capabilities of the acoustic waveguide by utilizing it in devices operating under conditions of high temperature, radiation, strong electromagnetic interferences and other negative factors.

Abstract: Embodiments are directed to a simple, tool-less, and automated connection between a transfer probe and a capacitive liquid level detection printed circuit assembly (PCA) for use in a clinical analyzer in an in vitro diagnostics (IVD) environment in a hospital or laboratory setting. Advantageously, a single user connection is required: a fitting that is used to attach fluid tubing of the transfer arm to a probe, resulting in a mechanical, fluid, and electrical connection between the probe and the transfer arm. A PCA comprises a plurality of spring-loaded pins and capacitive liquid level detection circuity. A probe comprises a primary tube nested within a secondary tube, wherein the primary tube and the secondary tube comprise respective heads at respective top portions thereof forming a set of electrically isolated surfaces. The fitting secures the probe within a transfer arm and establishes the connection between the PCA and the probe.

Abstract: A capacitor fuel probe comprises a plurality of capacitor segments which are superposed on one another along a probe axis. The capacitor segments are distributed into three sets and connected electrically in parallel within each set separately. A capacity measurement which is performed for all the sets allows determining a fuel level while taking into account a possible variation of a dielectric constant of the fuel parallel to the probe axis. Top height values hn of the capacitor segments are selected so that hn?1<hn·(Kmin?1)/(Kmax?1), for any integer n-value from 2 to N, N being the number of capacitor segments, n varying according a superposition order of the capacitor segments, and Kmin and Kmax being minimum and maximum values for a fuel dielectric constant which are prescribed for the capacitor fuel probe.

Abstract: A tank (1) of electrically conductive liquid (12) comprising an enclosure (2) for storage of the liquid (12) delimited by at least one wall (13), a capacitive sensor (5) for measuring the liquid level inside said enclosure (2), and a device (6) for processing the output signal of the sensor (5) outside of the enclosure (2) comprising, in order to form a capacitor, a dielectric (11) and a first frame (10) electrically connectable to a source (18) for supplying power and to the processing device. The first frame (10) is arranged outside the enclosure (2), the dielectric (11) can be at least partially interposed between said first frame (10) and the electrically conductive liquid (12) and the dielectric (11) is formed by at least one part (131) of the wall (13) delimiting the enclosure (2) suitable for coming into contact with the electrically conductive liquid (12) contained inside the enclosure (2).

Abstract: A robot includes a sensor including an electrode portion of a sensor for detecting approach of or contact with another object is formed on an outer surface or an inner surface of an exterior member, and in which a drive unit of the robot main body is controlled so as to avoid approach between the robot body and the other object based on an output signal of the sensor.

Abstract: The present disclosure generally pertains to devices and methods for determining propellant mass based on average measurements irrespective of the fluid orientation in a fuel tank. The device is useful in detecting fuel levels in tanks where the fuel is in motion, for instance in aircraft (i.e., undergoing varying acceleration maneuvers) or spacecraft (i.e., a microgravity environment). The devices and methods can also be used for determining the liquid in a surface tension screen liquid acquisition device (LAD), and particularly, the incipient breakdown as gas bubbles enter or are formed inside the LAD as the screen dries or heat transfer induces vaporization. The same basic electrode configuration can be used to stir the liquid to reduce thermal stratification and condense vapor bubbles.

Abstract: Methods and systems are provided for an integrated fuel composition-pressure sensor. In one example, the integrated sensor may include a set of cylindrical capacitors and a set of plate capacitors with a common capacitor element shared between the sets. A composition of fuel may be determined from the set of cylindrical capacitors and a pressure of fuel may be determined from the set of plate capacitors.

Abstract: The present invention provides a method of outputting a level of a capacitive level sensor which may be provided in a water trap of a fuel cell system and the method of outputting a level of a capacitive level sensor including a level sensor including a plurality of electrodes for measuring capacitance, and an upper electrode and a lower electrode which are able to be disposed adjacent to each other in the level sensor, including: (a) measuring a change in an output value of the lower electrode; and (b) measuring a change in an output value of the upper electrode.

Abstract: A liquid level detector for use in a pump control system comprises a chamber 20 for liquid, a liquid inlet 6 to the chamber 20, a liquid outlet 7 from the chamber and connectable to a pump, and a capacitive sensor comprising mutually spaced capacitive sensor elements (21, 22; 22, 23) forming a capacitance which is sensitive to permittivity within a region of the chamber proximate the capacitive sensor. The chamber is defined at least partially by a barrier member 25 and the capacitive sensor elements are provided on the barrier member outside the chamber.

Abstract: A sensor assembly is described herein that can automatically calibrate itself upon installation into an empty bin, eliminating the need to actually fill the bin to calibrate the level reading. The sensor will provide consistent measurement regardless of material properties (permittivity, density, temperature or moisture content). The capacitive nature of the sensor means that in some circumstances, it will sense the material through plastic/glass/fiber glass thereby allowing the sensor assembly to be mountable on the outside of a bin or container. The electrodes of the sensor system are designed to provide a continuous level reading.

Abstract: An electronic cigarette or similar vaporization devices include a liquid which is vaporized or atomized in an atomizer. An e-liquid detection system can verify that the e-liquid is acceptable for use in the device. The e-liquid detection system may detect one or more indicators, and/or physical or chemical properties of the e-liquid. The e-liquid detection system may also measure the e-liquid level in the device.

Abstract: A circuit for simulating a capacitance fuel probe, the circuit comprising: an input for receiving an alternating current (AC) excitation signal; an output for outputting an output signal representing a capacitance of the simulated fuel probe; a single reference capacitance; a first amplifier connected to the reference capacitance, the first amplifier being configured to cause a current flow through the reference capacitance; a second, variable gain, amplifier, the second, variable gain amplifier being configured to output an AC signal representing a multiple of the current flow through the reference capacitance, wherein the AC signal output by the second amplifier is used to generate the output signal.

Abstract: The present disclosure provides a vehicle and method for controlling the vehicle, which relates to a technology for reconstructing a screen to be displayed in a display area based on a display area of an external device held in a holding groove inside the vehicle. The vehicle includes: a holding groove configured to hold an external device when the external device is inserted thereto; an electrode positioned in the holding groove that is configured to transmit a frequency signal to the external device; a controller configured to generate image data to reconstruct a screen to be displayed on the external device according to information about a display area of the external device set up by the external device based on the frequency signal; and a communicator configured to transmit the image data to the external device.

Abstract: A measurement device has two electrodes in the liquid forming a capacitor the capacitance of which depends on the height of the liquid, a microcontroller connected to an electrode and having a capacitance determination circuit for determining first and second values of the capacitance of the capacitor respectively during charging and discharging of the capacitor, an oscillator circuit for generating signals at a reference frequency when the electrodes are not connected to the microcontroller, then at a variable frequency dependent on the height of the liquid when the electrodes are connected to the microcontroller. The microcontroller further includes a programmable logic device configured into a comparator circuit, and a frequency determination circuit connected to the programmable logic device so as to determine the variable frequency from the reference frequency and from the signals of the programmable logic device.

Abstract: A method for determining a filling level of a fluid tank in a motor vehicle, enables both a detection of an ascent or a descent of the motor vehicle with the aid of multiple pieces of position data ascertained in succession via a position determination system, and a plausibility check of the measuring value of the filling level sensor, in that a grade of an associated route section is ascertained for the ascertained position data, a selection of at least two route sections having different grades is carried out, and a measuring value of the filling level sensor to be expected is ascertained for each of them, and a comparison of the measuring values to be expected with the measured measuring values is carried out.

Abstract: A multi-capacitor liquid detection device and method(s) of use is described. Embodiments of the multi-capacitor liquid detection device can include at least two capacitors being separated by a predetermined height. The multi-capacitor liquid detection device can be implemented to detect and differentiate between different types of immiscible liquids by measuring and comparing a dielectric constant between two or more capacitors. The multi-capacitor liquid detection device can be implemented to determine if a false detection of a liquid has been made by one of the capacitors.

Abstract: An adhesive dispensing device includes a heater unit for melting adhesive, a fill system communicating with a receiving space for feeding the heater unit, and a reservoir for receiving melted adhesive from the heater unit. The dispensing device also includes a capacitive level sensor located along a sidewall of the receiving space such that the level of adhesive in the receiving space can be detected by sensing the difference in dielectric capacitance where the adhesive is located compared to where air acts as the dielectric. The size of the driven electrode produces a broader sensing window capable of generating multiple control signals corresponding to different fill levels of adhesive. The receiving space and reservoir are minimized in size so that adhesive is not held at elevated temperatures long enough to char or degrade.

Abstract: A capacitive level gauge assembly for a pressurized or liquefied gas container comprises a body with a base capable of being fitted in an opening of said container and an electrical circuit arranged in the body; electrode-carrying means are fitted in leakproof manner in said body and connected to said electrical circuit, said electrode-carrying means being configured to support two electrodes fixedly with an annular measurement space therebetween. The electrode-carrying means comprise a metallic support fitted in leakproof manner in the valve body and electrically insulated therefrom, the first electrode being fixed to said metallic support, and the metallic support being connected to the electrical circuit. The metallic support comprises at its free end a coupling means for the first electrode.

Abstract: An apparatus for detecting an oil level and a method for controlling the same, an apparatus for detecting oil flow and a method for controlling the same, and a method for controlling oil return using the detected oil level and the detected oil flow are disclosed. The level of oil stored in a compressor is measured at two or more positions. The frequency comparison scheme using two electrodes can correctly detect the level of oil stored in the compressor, a refrigerant state, and the level of mixed oils, and can determine an internal state of the compressor and a normal or abnormal state of the oil return system, such that the oil return control can be actively controlled. The flow of oil in the oil return pipe is detected so as to determine whether the oil is normally supplied in real time, such that a malfunction of the compressor is prevented and a valve state can be checked.

Abstract: Systems and methods for providing a smart hydration container or bottle which accurately tracks a user's liquid intake. The smart hydration container utilizes a new capacitive sensing technology which does not require a complicated design for capacitive conductive surfaces and provides accurate capacitive measurements which map to volume measurements. Through the use of calibrated data, the smart hydration container accurately measures capacitance “as a whole” of the entire container's contents even when the container is not resting upright. In some implementations, the smart hydration container utilizes a combination of capacitive sensing, motion sensing, position sensing, and/or temperature sensing to provide an accurate measure of liquid volume in the container. The capacitive sensor may be electrically shielded by a passive conductive sensor shield, a grounded conductive sensor shield, or an active conductive sensor shield.

Abstract: A slew rate detection circuit connected to a sensor detects when an analog electrical signal from the sensor indicates a slew rate that exceeds a threshold value, and generates an interrupt electrical signal when the slew rate is detected as exceeding the threshold value. A control circuit determines a measurement value of the physical property in response to receiving the interrupt signal. The control circuit is connected to an A/D converter, which converts the analog electrical signal into a digital electrical signal, and performs a plurality of sensing system operations including determining the measurement value of the physical property as a function of the digital electrical signal.

Abstract: A thermal trip assembly for use with a busbar includes a fastener, an insulating sleeve, a temperature sensor structured to sense a temperature of the busbar, and a thermal trip circuit structured to output a trip signal based on the sensed temperature. A portion of the insulating sleeve is disposed between the temperature sensor and the busbar. The fastener couples the insulating sleeve and the temperature sensor to the busbar with the insulating sleeve being in direct contact with a portion of the busbar.

Abstract: An electrode structure and apparatus for use in measuring oil-water constituents. The electrode structure comprises a first electrode (1) and a second electrode (2). The first electrode (1) has wrapped on the exterior thereof an insulating layer (104). The first electrode (1) and the second electrode (2) are fixed and insulatively connected via a supporting connector body (3). The first electrode (1) comprises multiple tubular conductive segment sub-electrodes (101) arranged along a first direction. Every two adjacent segment sub-electrodes (101) have formed therebetween a first gap. The second electrode (2) is arranged around the first electrode (1), and both are electrically connected to a signal and data processing unit (5).

Abstract: A method and apparatus for connecting a tube coaxially arranged around a measuring probe in a measuring probe unit of a fill-level measuring device comprising: a cable- or rod-shaped measuring probe and a tube coaxially surrounding the measuring probe. The measuring probe unit is connected to the container by means of a process connection element, wherein the measuring probe and the tube arranged coaxially around the measuring probe for the measuring probe unit are connected releasably to the process connection element. The coaxially arranged tube is connected releasably to the process connection element via a shape interlocking, threaded connection in a defined connection region, and the releasable, shape-interlocking, threaded connection of the coaxially arranged tube to the process connection element is secured by means of a radially directed deformation of the coaxially arranged tube in the defined connection region.

Abstract: A container for holding a volume of fluid and having a housing defining an interior for retaining the volume of fluid; at least one in-tank tilt sensor connected to a controller and disposed inside the housing for generating a signal corresponding to a level of fluid inside the housing; and a support material attached to the housing and connected to the at least one in-tank tilt sensor to mechanically support the at least one in-tank tilt sensor such that the at least one in-tank tilt sensor is not in direct contact with the fluid inside the housing. The in-tank tilt sensor detects a change in fluid level which may only be caused by tilting of the imaging device. When tilting is registered, protective action is taken to prevent fluid from leaking.

Abstract: A radio circuit includes a front-end module, a board, a liquid MEMS component, and a coupling component. The front-end module is implemented on at least one integrated circuit (IC) die and includes a variable circuit. The variable circuit is adjustable to facilitate an operational adjustment of the front-end module for a given operational condition of the radio circuit. The board supports the liquid MEMS component and supports, at least indirectly, the at least one IC. The coupling component electrical couples the liquid MEMS component to the variable circuit, wherein, based on a control signal, one or more characteristics of the liquid MEMS component is changed, which adjusts the variable circuit.

Abstract: An energy recovery device including: at least one capacitor with variable capacitance, the capacitor including a fixed electrode, a dielectric layer, and a liquid electrode; and a mechanism to inject an electric charge into the capacitor and to remove the electric charge therefrom, including a charge injection electrode forming a portion of the second face positioned upstream from the fixed electrode in the direction of displacement of the liquid electrode, and a charge removal electrode forming a portion of the second face positioned downstream from the fixed electrode in the direction of displacement of the liquid electrode.

Abstract: A liquid micro-electro-mechanical system (MEMS) capacitor includes a first capacitor plate, a second capacitor plate, a channel, a dielectric doped droplet, and a droplet activating module. The channel is implemented or embedded in one or more layers of a board and the dielectric doped droplet is contained in the channel. The droplet activating module operable to change the dielectric doped droplet with respect to the first and second capacitive plates, which are proximal to the channel and at a distance from each other, thereby changing a dielectric property of the liquid MEMS capacitor.

Abstract: A method for manufacturing a measuring apparatus for capacitive determining and/or monitoring of at least the fill level of a medium. The measuring apparatus has a probe unit and an electronics unit. During a measurement, the electronics unit supplies the probe unit with an exciter signal and receives from the probe unit a received signal, from which the electronics unit ascertains a capacitance value. The probe unit is coated with an insulation layer, the coated probe unit is connected with the electronics unit and inserted into a container containing a calibration medium, the coated probe unit is covered completely by the calibration medium and an associated received signal is gained, and, with the associated received signal, at least one adjustable component of the electronics unit is set.

Abstract: An energy recovery device including: at least one capacitor with variable capacitance, the capacitor including a fixed electrode, a dielectric layer, and a liquid electrode; and a mechanism to inject an electric charge into the capacitor and to remove the electric charge therefrom, including a charge injection electrode forming a portion of the second face positioned upstream from the fixed electrode in the direction of displacement of the liquid electrode, and a charge removal electrode forming a portion of the second face positioned downstream from the fixed electrode in the direction of displacement of the liquid electrode.

Abstract: One embodiment of the present invention relates to a variable capacitor that operates without moving mechanical parts. In this capacitor electrically conductive electrodes are separated by an enclosed chamber filled with an electrically conductive material. The electrically conductive material can freely vary its position within the chamber. The capacitance of the device will vary as position of the conductive material changes due to external mechanical motion (ex: rotation, vibration, etc.) of the device. Other embodiments of this device are also disclosed.

Abstract: A method is provided that includes, but is not limited to the steps of driving in an on-off manner in a period of time an electronic switch in series with a respective glow plug between the terminals of a d.c. voltage supply, sensing the glow plug voltage and the glow plug current, generating analogue sense signals representative of the time integral of the glow plug voltage and current, generating analogue reference signals corresponding to the digital values of corresponding control words, comparing the sense signals to the respective reference signals and modifying the corresponding control words so as to minimize the difference between the sense signals and the reference signals, calculating the average values of the sensed voltage and current on the basis of the values of the control words at the beginning and at the end of the “on” time of the electronic switch.

Abstract: A micro fluidic device and method for capacitive sensing. The device includes a fluid channel including an inlet at a first end and an outlet at a second end, a cavity region coupled to the fluid channel, and a polymer based membrane coupled between the fluid channel and the cavity region. Additionally, the device includes a first capacitor electrode coupled to the membrane, a second capacitor electrode coupled to the cavity region and physically separated from the first capacitor electrode by at least the cavity region, and an electrical power source coupled between the first capacitor electrode and the second capacitor electrode and causing an electric field at least within the cavity region. The polymer based membrane includes a polymer.

Abstract: A capacitive sensor assembly for measuring a level of fluent material in a container includes an electronics section for receiving and processing signals and an antenna probe operably associated with the electronics section. The antenna probe has an electrical conductor and an insulating layer that covers at least a portion of the electrical conductor. The electrical conductor is connected to the electronics section. An enlarged measurement portion is in turn connected to the electrical conductor for detecting the presence or absence of the fluent material. The enlarged measurement portion has a surface area that is larger than a surface area of the electrical conductor over an equivalent height or length to function as a first plate of the capacitive sensor assembly, with the fluent material to be measured functioning as a second capacitive plate. In this manner, a change in detected capacitance of the antenna probe is reflective of a level condition of the fluent material.

Abstract: Capacitive gauge comprising interdigital electrodes on an insulating substrate having the form of a hollow cylinder having an internal surface and an external surface, the interdigital electrodes being disposed on the internal surface of this cylinder.

Abstract: A microfluidic device and method for capacitive sensing. The device includes a fluid channel including an inlet at a first end and an outlet at a second end, a cavity region coupled to the fluid channel, and a polymer based membrane coupled between the fluid channel and the cavity region. Additionally, the device includes a first capacitor electrode coupled to the membrane, a second capacitor electrode coupled to the cavity region and physically separated from the first capacitor electrode by at least the cavity region, and an electrical power source coupled between the first capacitor electrode and the second capacitor electrode and causing an electric field at least within the cavity region. The polymer based membrane includes a polymer.

Abstract: Capacitors (10,20,40,50,70,80) having a fluid dielectric material that is transported or undergoes a phase change are disclosed. The dielectric medium change results in a change in the total dielectric constant of the material between the electrodes (12, 14, 72, 74, 81, 82), thus changing the capacitance of the capacitors. Transporting or phase changing the dielectric fluids into and out of a the electric field of the capacitor, changes the effective dielectric constant and the capacitance of the capacitor.

Abstract: A capacitive fill level measurement device with a fill level sensor having a plurality of sensor fields, electrical wires for electrically connecting the plurality of sensor fields to a multipole side of a selector switch, and a power supply and evaluation circuit electrically connected to a monopole side of the selector switch. The capacitive fill level measurement device can be made with simple production technology and thus economically for a host of different applications using a matrix of printed conductors which extend vertically and horizontally such that each horizontally extending printed conductor on one side is connected to one sensor field and on the other side connected to a vertically extending printed conductor. Each horizontally extending printed conductor is connected with a respective vertically extending printed conductor to form an electrical line or a part of an electrical line.

Abstract: An oil level/condition sensor includes a first level sensing tube, a common tube, and a second level sensing tube. The tubes are concentric to each other around a central axis. Moreover, the tubes are separated by plastic spacers which insulate the level sensing tubes from the common tube and maintain the concentricity of the tubes. Installed in the end of the first level sensing tube is a coupling/plug and disposed around the coupling/plug is a first condition sensing tube. The coupling/plug insulates the first level sensing tube from the first condition sensing tube and prevents fluid communication therebetween. A second condition sensing tube is attached to the second level sensing tube around the common tube and the first condition sensing tube. A ring-shaped insulator electrically isolates the second condition sensing tube from the second level sensing tube.

Abstract: An interceptor for removing grease from an effluent stream containing grease and water may be queried remotely to check it status. An output signal indicative of the amount of grease is transmitted over a telephone line to a telephone or computer or other remote station, or wirelessly to a remote receiver. The status is preferably also indicated locally with visual and/or audible signals. The grease depth level sensor is preferably a capacitive level sensor operative to sense the amount of water in the body of effluent thereby to determine the amount of grease in the body of effluent. The interceptor may include electric circuitry for effecting manual or automatic calibration of the sensor. The sensor may be adapted to be retrofitted to an existing tank made from either metal or plastic.

Abstract: Reservoir volume in a drug delivery device is sensed by providing a capacitor, the capacitance of which varies with bellows position or, alternatively, with the amount of propellant liquid absorbed in a dielectric material. In one embodiment, a capacitance is provided between a surface of the bellows, which acts as a first capacitor plate, and a conductive surface disposed proximate the bellows, which acts as a second capacitor plate. As the bellows moves from its extended full position to its collapsed empty position, the area of overlap, and therefore the capacitance between the first and second plates varies from a maximum value to a minimum value. In another embodiment, a variable capacitor is provided with an absorbent material. The absorbent material absorbs the liquid phase of the propellant in the pump housing and acts as a dielectric between two stationary conductive plates provided in the housing. The amount of liquid propellant absorbed in the absorbent material varies with the reservoir volume.

Abstract: A fringing-field capacitive liquid level sensor comprising an electrically insulating substrate, having a first and a second pattern of conductive capacitance plates plated on the substrate. Each pattern constitutes a fringing-field capacitor having a capacitance the value of which is both dependent on the liquid level and dependent on the dielectric constant of the liquid. The ratio of the two capacitances, however, is proportional to the liquid level and independent of the dielectric constant of the liquid. The fringing-field capacitive liquid level sensor may be used for measurement of liquids of substantially any dielectric constant without requiring full-scale calibration or knowledge of, and calibration for, dielectric constant of the liquid to be measured. Compensation for tilt angle can be provided through the addition of a second level sensor.

Abstract: An automatic draw-off grease interceptor 10 includes a separation tank 12 defining a chamber 40. An inlet 24 delivers an effluent stream of grease and water into the chamber which separates into a thicken layer of grease atop a water layer. A pump 70 is included for pumping grease from the chamber when the grease has reached a predetermined level 120. A conductive probe 90 extends vertically in the separation tank 12 from a location above the upper surface of the effluent to a location below the predetermined level 120. An R/C oscillator circuit 112 continuously measures the amount of water in the chamber by measuring the capacitance between the probe and a wall of the tank. A controller 116 actuates the pump in response to the R/C oscillator circuit measuring a capacitance corresponding to an amount of water in the tank when the grease layer reaches the predetermined level.

Abstract: The subject matter of the present invention is the optimization of a capacitive liquid level sensor which is suitable, in particular, for determining the location of a boundary layer 12 between water 10 and oil 11 in a separator tank. The known sensor principle is based on measuring the environmentally dependent capacitance between neighboring electrodes 13, 4; 4, 5; 5, 6 of a rod-shaped probe 1. According to the invention, the probe 1 is designed such that large ionic double-layer capacitors occur on the electrodes 4, 5, 6, 13 in the more conductive medium 10, and small capacitors occur between electrodes 4, 5, 6, 13 in the insulating medium 11. For this purpose, the electrode height h is selected to be large, the ratio of the electrode height h to the electrode spacing a is preferably selected to be in the range of 1<h/a<6 and, in particular, the measuring frequency f is selected to be in the dielectric cut-off frequencies of the media 10, 11.

Abstract: Capacitive measurement probe (6) for measuring the level of a liquid in a tank (1), of the type comprising a body (7) for mounting the probe and a first plate (8) which is supported by the body and is intended, together with a second plate (41), to form a measurement capacitor intended to be connected to an electrical voltage supply, which plates are intended to be partially immersed in the liquid and to define, between them, a space for receiving the liquid. The first plate (8) is mounted on the body so that it can be adjusted between at least a high measurement position and a low measurement position.

Abstract: In order to monitor the consumption of a normally electrically conductive product contained in a storage chamber of a reservoir made of electrically non-conductive material, the storage chamber is disposed in a capacitive arrangement and a measurement procedure is defined, according to which, in response to an excitation signal applied to the capacitive arrangement, a measurement signal is obtained (at 122), one characteristic of which has an amplitude which varies substantially with the quantity of product contained in the storage chamber. Before deducing the value of information representing the quantity of product available in the reservoir from this amplitude, the measurement signal has filtering applied to it, according to which it is multiplied by a reference signal of frequency at least approximately equal to that of the excitation signal (at 121) and the multiplied signal is applied to a low-pass filter.

Abstract: A fault protective device (48) for limiting the maximum current and voltage applicable to electronic components and wiring (26, 30) located in the fuel tank (10) of an aircraft. Particularly, a fuel gauging system circuit (18) extends from a generator (20) located outside the tank to at least one probe (14) located in the tank and from the probe to instrumentation (24) outside the tank. The device is electrically coupled to the circuit at the tank wall (28) and includes a voltage clamp (50) and series inductor-capacitor resonant circuit (46), so that the resonant circuit provides a low series impedance when applied with a signal at the operating frequency of the input signal applied by the generator but provides a high series impedance when experiencing a signal of a different frequency indicative of a system fault.

Abstract: A sensor arrangement determines a condition and level of a liquid in a container. A first sensor has first electrodes forming a first measuring chamber communicating with the liquid and supplies a signal for determining an impedance of the first sensor and a condition of the liquid in the container. A second sensor has second electrodes forming a second measuring chamber communicating with the liquid via the first measuring chamber and supplies a signal for determining an impedance of the second sensor and a level of the liquid in the container. Electronic devices are coupled to the first and second sensors, and determine the impedance of the first and second sensors and the condition and level of the liquid in the container.

Abstract: Determination of the quantity of consumable product present in a reservoir, for example the quantity of ink present in the reservoir of an inkjet printing device. According to the invention, the movable reservoir can be engaged in the dielectric space of a capacitor consisting of two plates, a signal generator applies a signal to the capacitor and the reservoir is moved, a comparator changes state when a threshold is reached and the distance travelled by the reservoir makes it possible to determine the quantity of product situated therein.

Abstract: A capacitive filling level sensor has a first capacitive sensor element arranged close to a fluid whose filling level is to be detected, a second capacitive sensor element arranged close to a fluid whose filling level is to be detected, and a switched-capacitor measuring circuit, which is connected to the first and second capacitive sensor elements and which detects the capacitance values thereof. The switched-capacitor measuring circuit produces in response to the detected capacitance values a signal indicative of the filling level. The first capacitive sensor element and the second capacitive sensor element are each defined by two wires of a ribbon cable having at least five wires, the fifth wire extending between the wires which define the capacitive sensor elements, and being connected to ground.