Abstract: Radar is used to measure not only the level of slag on molten steel but also its thickness; the measurement is used to calculate the volume of slag, and, in turn the amount of additives for slag treatment. Time-of-flight data are used to identify peaks representing the distances of the surfaces of the slag and the surface of the underlying steel. The concept is applicable to other materials of differing composition, and particularly where the underlying material is relatively more conductive than the overlying material.

Abstract: An engine oil level detector, which includes a casing, a cover covered on the casing and defining two communicated air chambers, a diaphragm covered on the air chambers of the cover, the diaphragm having first and second tubular coupling portions, an electromagnetic valve mounted in the casing and controlled to reciprocate the first tubular coupling portion, a solenoid switch controlling a signal lamp, a magnet moved with the second tubular coupling portion to turn on/off the solenoid switch, and a suction tube connected between the first air chamber and the engine oil tank in a vehicle engine, wherein the magnet is moved with the second tubular coupling portion of the diaphragm toward the solenoid switch, causing the solenoid switch to be turned off when the oil level in the engine oil tank drops below the suction tube and the electromagnetic valve is turned on; the magnet is moved with the tubular coupling portion of the diaphragm away from the solenoid switch, causing the solenoid switch to be turned on wh

Abstract: A filling level measuring device operating with microwaves and to be fastened on a container (3) is provided, the device having a housing (11) and a rod-shaped antenna (7) pointing into the container (3) and the device being designed such that the antenna (7) does not transmit or receive microwaves in the region of a measuring device fastening and the transmitted power is not impaired by condensate or moisture. According to a first solution variant, the antenna (7) is fastened in the housing (11) and a section of the antenna (7) in the region of the measuring device fastening is surrounded by a metallic sleeve (8). According to a second solution variant, a sleeve (8a) in which the antenna (7) is fastened is formed onto the housing (11).

Abstract: Liquid gauging system for liquid in a container includes a plurality of sensors; each of the sensors measuring a respective parameter of the liquid in the container and producing a sensor output related to its measured parameter; there being at least two sensors that measure different parameters of the liquid; and a processor that receives the sensor outputs and determines, based on the sensor outputs, a quantity of the liquid in the container; the processor determining the quantity by executing at least one sensor fusion algorithm that is based on a set of relationships between the measured parameters and the quantity. The gauging system can also include a data fusion process for determining quantity based on a plurality of quantity measurements.

Abstract: A liquid transfer device for an analysis unit includes a transfer needle having a tip, and a capacitive liquid level detector for detecting immersion of the tip of the needle into an analysis liquid by detecting a change in capacitance between a signal electrode and a counter electrode. The analysis liquid is contained in a vessel. The capacitive liquid level detector includes a signal electrode, a counter electrode, and a detection circuit connected to the signal electrode and the counter electrode. The detection circuit detects a change in capacitance between the signal electrode and the counter electrode. A temperature dependent detection resistor is disposed adjacent the tip of the liquid transfer needle. The tip of the liquid transfer needle and the temperature dependent detection resistor are movable into and out of the analysis liquid. The detection circuit includes a current supply for supplying current to the detection resistor.

Abstract: A bathtub water level warning device for activating an audible and/or visible warning indicator when the water level in a bathtub approximately reaches a predetermined level, comprising a watertight case including a float element, a tubular stem element and a tubular pivot element. The alarm device is an independent device which floats free of the bathtub upon the bathtub reaching a filled condition, therefore allowing removal or inclusion of the device in a bathtub as desired by a user, such as during filling only. The alarm device includes a power source, a gravity switch, and an audible and/or visible warning indicator is internally mounted in the alarm device. Gravity causes the switch to close when the alarm device is in a substantially vertical orientation.

Abstract: A connector is provided for detachably connecting a level transmitter to a container. The container has a first connector portion fixed to the level transmitter and a second connector portion fixed to the container. In order to reduce the risk of damage to the level transmitter, the first and second connector portions are engaged without the need for relative rotation between the first and second connector portions.

Abstract: A detection apparatus that utilizes a CR oscillating circuit and detects residual ink quantities in an ink cartridge. The CR oscillating circuit is constructed from a capacitor C in which the capacitance value changes according to the residual ink quantity and a logic integrated circuit. A pulse signal frequency is oscillated by the logic integrated circuit based on the quantity of residual ink. Therefore, the quantity of residual ink is detected by counting the number of pulses of the pulse signal over a predetermined period of time based on the frequency of the pulse signal output from the logic integrated circuit. Thereby, digital processing can be conducted by directly using logic signals output from the logic integrated circuit without using an A/D converter.

Abstract: A fluid level detector according to the invention comprises a substrate formed of a heat-insulative material and one or more thermoresistive sensor elements located on the substrate that is adapted to be immersed in a fluid. A current source is connected to the sensor element for producing a current through the sensor element during a predetermined time period. The current heats the sensor element and causes a change in voltage across the sensor element at least during the time period. The amount of change in voltage during the time period is reflective of the fluid level, since the fluid serves as a heat sink for the sensor element. The voltage is measured across the sensor element and a voltage slope is determined. The determined voltage slope is indicative of fluid level.

Abstract: A system for measuring level of material in a vessel that includes a transmission line probe adapted to be positioned for contact with material in the vessel. Electronics are coupled to the transmission line probe for launching microwave radiation along the probe and detecting radiation reflected by the electrical impedance discontinuity presented at the air/material interface in the vessel. Level of the air/material interface within the vessel is determined employing time domain reflectometry techniques, and is displayed as a continuous function over a predetermined range. The system range is calibrated by means of a target selectively manually positionable along the probe rod while the probe is disposed outside of the vessel. First and second signals are selectively stored in the system electronics with the target disposed at positions along the probe rod corresponding to the ends of the material level measurement range.

Abstract: A method and apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable for a material in a vessel. The method includes the steps of determining an initial reference signal along a probe, storing the initial reference signal as an active reference signal, periodically detecting a TDR signal along the probe in the vessel, and computing the output result using the TDR signal and the active reference signal. The method also includes the steps of determining an appropriate time for updating the active reference signal, automatically computing an updated reference signal at the appropriate time, and overwriting the active reference signal with the updated reference signal for use in subsequent computations of the output result.

Abstract: The subject matter of the present invention is a method and a device for capacitive liquid level measurement which are particularly suitable for determining liquid level between adhesive media 10, 11 of different conductivity. The known sensor principle is based on the fact that the environmentally dependent capacitance is measured between neighboring electrodes 13, 4; 4, 5; 5, 6 of a rod-shaped probe 1. According to the invention, the probe 1 has electrodes 4, 5, 6, 13 with covers 7 of different thicknesses d.sub.i. The effective thickness d.sub.s /.epsilon..sub.s of an insulating pollutant film 14 can then be determined by capacitance measurements between at least two pairs of electrodes 4, 5, 6, 13. The influence of a conductive pollutant film 14 on the capacitance signal can be eliminated by selection of at least one suitable measuring frequency.

Abstract: An indicator providing visual information of the level of bulk material in a bin has rotatable visual members with bright and dark colored surfaces covered with a transparent lens. A actuator located within the bin is operatively coupled to the visual members to turn the visual member to an ON position exposing the bright colored surface to a person when bulk material engages the actuator and to an OFF position exposing the dark colored surface to a person when the actuator is free of bulk material whereby the person can determine the level of the bulk material in the bin. The visual members are also provided with a device that triggers a sensor that activates a remote indicator providing data as to the level of bulk material in the bin.

Abstract: The process for generating at least one warning signal relating to the level in a tank (3) for storing a product (4) comprises the following steps:the storage level of the product in the tank, together with the values of the product quantity consumed during predefined time intervals are determined,these values are placed in memory together with the associated measurement instants,at other successive instantsthe values placed in memory of the product quantity consumed are used to calculate a value of the estimated quantity of product which will be consumed in the future,this estimated value is subtracted from the last measurement value so as to obtain an estimated value of the storage level at a future instant,this estimated value of the storage level is compared with a preset threshold, anda warning signal is generated if the estimated value is less than the preset threshold.

Abstract: The invention provides a software tool in a PC environment, which can be used for planing and analyzing a mission of communication satellite. Input data required for predicting and estimating the amount of fuel remaining in the satellite is automatically connected to the main program, to create the remaining fuel quantity value in the result file automatically. The invention allows the satellite operator to easily perform the computation of the remaining fuel quantity in the analysis of satellite mission, and to arrange related data.

Abstract: Disclosed is an optical sensor used for remote laser level monitoring in liquid storage vessels. The sensor is mounted directly to a standard tank nipple, located on top of the vessel, by a threaded connecting means and is linked to a laser measurement device via fiber optic cabling. The level in the vessel is measured as a function of the time required for a laser signal to be transmitted from the sensor, reflected off the liquid surface and returned to the receiver lens located in the sensor.

Abstract: A bathing basin monitoring system is provided including a housing with a couple adapted for securing to a bathing basin. A speaker is mounted on the housing for emitting audio signals. Also included is a moisture/temperature sensor assembly having a moisture sensor positioned at a desired water line for generating an activation signal upon the detection of water and a temperature sensor for generating a temperature signal indicative of a temperature. At least one display is mounted on the housing for depicting numeric characters. A controller is positioned within the housing and connected to the speaker and sensors of the moisture/temperature sensor assembly. The controller serves to display a current temperature detected by the temperature sensor on the display and emit an alarm from the speaker upon the receipt of the activation signal.

Abstract: A device for measuring and monitoring the volume of liquid in a container comprises an adapter for mounting the device in an opening in the top wall of the container. The adapter supports a beam onto which one end of a float is connected such that the free end of the float extends substantially vertically into the container. A strain gauge is disposed on the beam so that the measuring direction of the gauge is parallel to the main axis of the beam. The device can also include a sensor for measuring physical parameters of the container. A processor is connected to the strain gauge and any sensor to take data from those input devices. During a calibration operation, a measurement function is derived to correlate strain gauge readings to the volume of liquid in the container. The function is recorded in a processor which takes data from the strain gauge and calculates the actual volume of liquid in the container. An output component displays the measurement.

Abstract: A disposable fluid level sensor is configured for determining the level of fluid in a container. A flex circuit or other electromagnetic sensor is coupled to a processing module having a power supply, the flex circuit being mounted at a selectable location by an adhesive patch which holds the sensor flush against the container. The processing module hangs from the sensor's antenna, and provides a human perceptible indication, such as a flashing light or an audible alarm, when the fluid level drops below a desired point as determined by the sensor. The sensor detects the change in fluid level by transmitting an electromagnetic signal and determining whether there is a change in reflected or resonated energy.

Abstract: A water level detecting and alarm system for informing a user when a water level within a bathtub has risen to or above a desired level. The system includes a housing having an opening at one end forming a lower lumen and a closed end opposite thereof. A securing means is attached to a side of the housing for adjustably securing to an interior surface of the bathtub corresponding to desirable water level. A partition within the housing is oriented traverse to a longitudinal axis of the housing. A tube projects in and through the partition coaxial with the longitudinal axis of the housing. A shaft has a flanged end and a lower end, and slidably projects through the tube. A float slidably projecting in the lower lumen of the housing for having a latitude similar to the water level within the bathtub. The float is secured to the lower end of the shaft for elevating and descending the shaft in a manner corresponding to the water level.

Abstract: A method for determining an optimized solution of positions for N liquid surface sensors used to gauge quantity of liquid in the container, comprising the steps of:a) defining geometric limits of the container in terms of coordinates of a three axis (x,y,z) reference coordinate system assigned to the container;b) defining a chromosome structure for an individual, wherein said chromosome structure identifies a solution in terms of position data of the N sensors;c) determining a population of individuals wherein each individual in said population is a possible solution within said geometric limits; each individual having a respective chromosome; andd) executing a genetic algorithm on said population to identify a solution that meets a performance criteria as measured by a predetermined cost function.

Abstract: An advanced signal processing technique accurately discriminates and estimates a small sinusoidal signal in close proximity from one or more large sinusoidal signals. The technique involves using digital processing techniques to accurately estimate the frequency (96), amplitude (94) and phase (98) of the one or more large sinusoids and then using this estimate to obtain an accurate estimate of the small sinusoidal signal by subtracting the large sinusoid from the data to obtain a residual and reprocessing the residual.

Abstract: A method and apparatus for controlling the level efficiently, and rate of removal of water from an oil or gas well using a progressive cavity pump operated by a rotating drive shaft extending downwardly from ground level to the pump comprises a sensor that detects the downward force on the shaft produced by the dynamic operation of the pump; and a control mechanism responsive to the output from the sensor that correlates the downward force on the pump with liquid depth in the casing and controls pump speed in order to achieve a desired rate of liquid removal from the casing and a desired ultimate depth level of liquid in the casing above the pump. A novel fluid pressure sensing mechanism mounted on the shaft at ground level permits the shaft to rotate while providing an accurate reading of the downward force on the shaft.

Abstract: A fail-safe fluid transfer control apparatus has full redundancy in the response to various inputs such as overfill probe signals, ground detection signals, and the like. Independent microprocessor controllers independently evaluate the inputs and each output control signals to close a respective relay when the inputs indicate that fluid transfer may commence. The relays are arranged in series such that both must be closed for a fluid transfer to commence. The control signals from each controller include a static signal and an alternating signal, both of which must be properly output to close its respective relay. Each controller monitors the state of each relay, and discontinues its control signals if either relay appears to be malfunctioning. Each controller runs an different, independently written firmware program to process the detected inputs to prevent a common firmware error.

Abstract: Ultrasonic apparatus determines the fluid depth, volume, and temperature in a storage tank. A system description for monitoring an underground storage tank containing gasoline is described. The system determines the water's and gasoline's depth, volume, and temperature. The apparatus consists of a remote console, ultrasonic probe, and interconnecting cable. The remote console contains a display to report tank information and a computer to operate the probe. The probe consists of an ultrasonic transducer above the bottom of the probe facing upwards to transmit and receive ultrasonic signals, vertically spaced reflectors and a temperature sensor to measure fluid temperature.

Abstract: A fail-safe fluid transfer control apparatus has full redundancy in the response to various inputs such as overfill probe signals, ground detection signals, and the like. Independent microprocessor controllers independently evaluate the inputs and each output control signals to close a respective relay when the inputs indicate that fluid transfer may commence. The relays are arranged in series such that both must be closed for a fluid transfer to commence. The control signals from each controller include a static signal and an alternating signal, both of which must be properly output to close its respective relay. Each controller monitors the state of each relay, and discontinues its control signals if either relay appears to be malfunctioning. Each controller runs an different, independently written firmware program to process the detected inputs to prevent a common firmware error.

Abstract: The monitoring system for a separation reservoir containing at least two mediums, at least one medium floating on another medium includes: means for determining the levels of the upper and lower boundaries of the floating medium; means, responsive to the means for determining, for comparing the upper and lower boundary levels to reference levels in the separation reservoir; and means, responsive to the means for comparing, for indicating the condition of the reservoir.

Abstract: An apparatus (50, 100, 150) for sensing a surface level (20) of fluid (12) includes a generally cylindrical central conductor (16, 102, 152) for connection to a pulse signal source (26) with a reduced diameter end (28, 104, 154) and an opposite end (24, 124, 168); a generally tubular outer conductor (14) concentric with the central conductor for connection to the pulse signal source and having one open end (32) adjacent the central conductor reduced diameter end and an opposite open end (18) adjacent the central conductor opposite end, the central conductor and the outer conductor forming a transmission line for pulse signals generated by the pulse signal source and a cavity (C) between an interior wall surface of the outer conductor and an exterior surface of the central conductor; a non-metallic seal (54) mounted at the outer conductor open end for sealing the cavity, the central conductor reduced diameter end extending through a central aperture (52) formed in the seal; a circuit board (58) for mounting th

Abstract: A waveguide for microwave radar level gages that includes a process sealed barrier in the waveguide that is impedance matched with bore transition sections of the waveguide at opposite ends thereof. The impedance matching results in positioning of the tapered end of the barrier offset from the ends of the bore transition sections.

Abstract: A probe (16) for use in measuring the level of fluid (12) in a tank (14) based on time-domain reflectometry detection utilizes a pair of flexible conductors (26, 28). The conductors (26, 28) may be removably placed in the tank (14) in a mounting bracket (32) secured to the tank (14), by sliding the conductors (26, 28) into the bracket (32), at one of a plurality of spacings. The selection of spacing of the conductors (26, 28) is based on the type of fluid utilized in the tank (14). The conductors (26, 28) are flexible to allow conformance to the contour of the tank (14).

Abstract: A secondary seal assembly is used with a process instrument including a probe assembly and an electric housing assembly. The probe assembly includes an adaptor receivable in an opening of a process vessel, a probe extending through the adaptor into the process vessel, and a primary seal between the probe and the adaptor. A probe terminal provides an electrical connection between the probe and the electric housing assembly. The secondary seal comprises an elongate extension housing adapted to be mechanically connected at one end to the adaptor and at another end to the electric housing assembly. A shaft insert is received in the extension housing having a terminal at each of opposite ends, a first terminal for providing an electrical connection to the electric housing assembly and a second terminal for providing an electrical connection to the probe terminal. A seal between the shaft insert and the extension housing provides a secondary seal to the process vessel.

Abstract: A foldable water tank remote level detector system is provided including a fire truck having a side extent with an analog gauge mounted thereon. The analog gauge has an indicator pivotally coupled thereto for pivoting between an empty indicia and a full indicia. As such, the gauge is adapted for indicating a level corresponding to a level signal upon the receipt thereof. Also included is a water level sensor situated within a body of water distant the fire truck. The water level sensor is adapted to continuously generate a level signal corresponding with a level of the water within the body of water. Finally, an extension cord is provided having a first end connected to the water level sensor and a second end connected to the gauge outlet of the fire truck thereby transmitting the level signals to the analog gauge.

Abstract: A liquid level sensing apparatus, and related method, that utilizes a tuning fork assembly to detect the presence of not only a liquid or air at a particular location within a container, but also a solid material at that location. The tuning fork assembly includes an excitation transducer and a receiving transducer mechanically coupled to a pair of paddles that are exposed within the container, and a phase-locked loop control system applies an excitation signal to the excitation transducer having a frequency that is regulated to track the tuning fork's resonant frequency. A comparator compares that resonant frequency with a prescribed threshold, to determine whether the tuning fork assembly is disposed in air or a liquid. A failure of the phase-locked loop control system to lock the frequency of the excitation signal at any particular frequency indicates that the tuning fork assembly is over-damped and likely contacted by a solid material.

Abstract: An overfill prevention device for storage tanks includes an elongate tubular housing having a liquid flow passageway. A normally open main valve and a normally closed vapor retaining bleed valve are associated with the fluid passageway. Closure of the main valve interrupts the primary flow of liquid through the passageway and closure of the bleed valve prevents any further liquid from entering the tank and also prevents the escape of vapors from the tank. Operation of the main valve is controlled in significant part by a valve latch assembly which is carried by the housing and a relatch assembly which is carried by the main valve. The relatch assembly ensures operative engagement of the main valve with the valve latch assembly upon movement of the main valve from the intermediate position to the open position. Operation of the main valve and vapor retaining bleed valve is also controlled indirectly by a plurality of floats which are maintained in a float chamber extending adjacent the liquid passageway.

Abstract: A liquid tank includes a tank body forming a reservoir for gasoline G, a flexible partition film 1 arranged in the tank body 1 to divide a space in the tank body into two vertical spaces, a float positioned on the gasoline G, an arm 3 for converting a high and low position of the float 3 into a rotational position of the arm 5, and a potentiometer 5 for detecting a position of the flexible partition film. Since the gasoline G is covered with the partition film, the gasoline G does not vaporize into the air in the tank body an. Even if the gasoline surface is slanted to the tank body an by an acceleration of the vehicle, the flexible partition film serves to restrict the inclination of the surface. Therefore, it is possible to precisely a residual amounts of the gasoline G irrespective of the inclination.

Abstract: A liquid level sensor unit outputs a voltage value, which corresponds to a measured liquid level, to an anti-slosh circuit that provides a fast timing rate during the initial condition of the circuit and a slow timing rate during the normal operation of the circuit. The anti-slosh circuit further includes a low liquid level warning circuit and a power-on-reset circuit. The system timing rate can be externally controlled by connecting an RC circuit to the improved anti-slosh circuit. A customer defined reference level for low liquid warning is also possible. The entire circuit is included on a single, monolithic integrated circuit. An input pin receives the signal from the fuel tank. An output pin drives a liquid level gauge.

Abstract: A method and apparatus for processing a time domain reflectometry (TDR) signal having a plurality of reflection pulses to generate a valid output result corresponding to a process variable in a vessel. The method includes the steps of establishing an initial boundary signal before the process variable is locates in the vessel, storing the initial boundary signal, detecting the TDR signal, and determining a baseline signal by subtracting the initial boundary signal from the TDR signal. The method also includes the steps of establishing a signal pattern having a time range based on the width of reflection pulses in the baseline signal, comparing the baseline signal to the signal pattern until a reflection pulse in the baseline signal matches the signal pattern, determining a maximum value of the reflection pulse that matches the signal pattern, and calculating an output result based on the maximum value.

Abstract: A method and apparatus for continuously monitoring fluid level in an oil well, by measuring changes in the weight of the oil well tubing which result from changes in the buoyancy of the tubing caused by the rise and fall of fluid level within the oil well. In the apparatus of the invention, a transducer is either affixed to the downhole tubing of the oil well, or alternatively, is affixed to the drive head support structure of a well having a progressive cavity well pump. The transducer continuously senses changes in the weight of the tubing as the buoyancy of the tubing changes in proportion to the rise and fall of fluid level within the well. The transducer is preferably connected to a control unit which, in turn, is connected to the pump motor and which functions to automatically control the pump motor as a function of fluid level within the well.

Abstract: A level sensor for use in a process application measures height of a product in a tank. The level meter includes a microwave feedhorn directed into the tank, an electronics housing spaced apart from the feedhorn and a microwave waveguide extending therebetween. A microwave transducer in the housing couples to the waveguide and sends and receives microwave signals. A microprocessor in the housing identifies echoes from the microwave signals which are generated and sensed by the microwave transducer. The microprocessor determines height of the product based upon a microwave echo from the product and a microwave echo from the feedhorn. The microprocessor compensates for the effect of propagation delay through the waveguide on height measurements with the feedhorn echo and provides an output related to height of the product in the tank.

Abstract: A method for measuring the water level of a reservoir, a larger river and an underground water and an apparatus thereof comprises a waveguide tube selected in a predetermined length, on the upper portion of which a sonic pulse generator is mounted, and a plurality of sonic receivers (first, second, third . . . nth), such as a microphone, arranged at an interval l from each another, in which the sonic pulse generator generates sonic impulses in a predetermined period, the receivers receive impulses divided into advancing waves and reflecting waves in turns, these impulses are amplified/wave-shaped to be applied to a microprocessor, and the microprocessor measures the time interval t.sub.1 between the advancing wave and the reflecting wave received by first sonic receiver and the time interval t.sub.n-1 between first sonic receiver and the n-1th sonic receiver located close to the water surface so as to calculate the water level L.

Abstract: A level detector or proximity detector for materials capable of sensing through plastic container walls or encapsulating materials is of the sensor. Thus, it can be used in corrosive environments, as well as in a wide variety of applications. An antenna has a characteristic impedance which depends on the materials in proximity to the antenna. An RF oscillator, which includes the antenna and is based on a single transistor in a Colpitt's configuration, produces an oscillating signal. A detector is coupled to the oscillator which signals changes in the oscillating signal caused by changes in the materials in proximity to the antenna. The oscillator is turned on and off at a pulse repetition frequency with a low duty cycle to conserve power. The antenna consists of a straight monopole about one-quarter wavelength long at the nominal frequency of the oscillator.

Abstract: In a remaining fuel amount measuring apparatus, a CPU captures remaining fuel amount data detected by a fuel sender unit at prescribed periods through a voltage conversion circuit and A/D conversion circuit, compiles the captured remaining fuel amount data into blocks each composed of a prescribed number of data samples to be successively stored in a RAM. The CPU reads the block data as necessary and subjects the read data to data processing such as simple averaging, weighted averaging or removal of abnormal values. The CPU displays the remaining fuel amount after the data processing on a fuel meter.

Abstract: Slow wave, time-domain reflectometer based point level sensors and instruments. Such sensors and instruments include a transmission line having an inner conductor, an outer shield that extends over that inner conductor so as to define a gap between the inner conductor and the outer shield, a dielectric material that fills the gap, except at a point, thereby defining a space, and an access opening for enabling a material being sensed to fill the space when that material is present. According to the invention the dielectric material has a permittivity substantially different from the material being sensed. Further included are a pulse generator for generating pulses on the transmission line, and a processing unit for determining whether the material being sensed fills the space. Beneficially the inner conductor is helically wound around a core, creating a slow wave transmission line.

Abstract: A description is given of a sturdy device for establishing and/or monitoring a predetermined filling level in a container, which device exhibits a housing (1), two oscillating rods (3, 4) projecting into the container, a first diaphragm (2) which is fixedly clamped, at its border, into the housing (1), a second diaphragm (6, 6') which is arranged parallel to said first diaphragm in the interior of the housing (1), a piezoelectric element (7, 7') which is arranged on the second diaphragm (6, 6') and is intended for receiving and converting oscillations into an electric output signal and for inducing bending oscillations in the second diaphragm (6, 6'), and in the case of which device the mode of oscillation produced by the piezoelectric element (7, 7') corresponds to the mode of oscillation utilized for inducing oscillation in the oscillating rods (3, 4).

Abstract: In a motor vehicle which includes a reservoir for holding fluid, a device for determining whether the fluid level within the reservoir exceeds a desired level, the reservoir having an aperture and a standpipe sealingly engaged with the reservoir at the aperture. The standpipe defines a passage for the flow of excess fluid from the reservoir and a proper fluid level in the reservoir. A plug selectively prevents passage of the fluid through the standpipe out of the reservoir.

Abstract: The apparatus measures the liquid volume of a liquid or liquids held in one or more containers. This apparatus has no moving parts and includes an open-ended dynamic pressure tube standing in each container with its open tube end at the lowest point of the container on the bottom surface of it and a pressure measurement converter closing the other tube end so as to form an air column between the pressure measurement converter and a liquid level in it. The apparatus also includes an electronic analyzing device (3,4) including an electronic circuit (3) connected electrically to the pressure measurement converter and producing an electronic signal characteristic of a liquid volume in the container and a digital meter for displaying a volume reading.

Abstract: In cases of application where the critical temperature occurs or could occur, safe monitoring of the level of the liquid was not possible heretofore because the physical properties of the liquid and of the gaseous medium present above the latter in the container no longer differ at this temperature. The method includes the temperature in the container in the monitoring of the level of the liquid. Below a lower comparative temperature value (Tu), the output signal of the evaluator unit is determined by the measuring signal of the level sensor. The measuring signal of the level sensor is disregarded above this value (Tu). The evaluator unit supplies an output signal that is on the safe side with respect to the level of the liquid. The comparative temperature (Tu) is below the critical temperature to an extent such that the inaccuracies in the measurement of the level sensor and the temperature sensor have no interfering effect.

Abstract: An ink jet pen supply cartridge having a spring biased ink reservoir with a visual indication of remaining ink quantity. The reservoir tends to collapse laterally as the ink supply decreases due to differential pressure exerted thereto. The spring-reservoir is contained in a rigid cartridge and a pair of flexible tape members are cemented or welded, one to each side of the spring-reservoir, and extend generally parallel toward a narrow end surface of the cartridge at which they overlap and can be viewed through a window. The overlapping relationship of the tape members provide ink quantity indicia which change as the spring-reservoir collapse draws them past each other.

Abstract: A galvanic cell is formed when ground water within a sump reservoir, tub or other pool, rises to contact electrodes constructed of dissimilar metals, the electrodes mounted in a bridge, with recessing, expansion brackets, to facilitate covering the sump hole and including an alarm device adapted to provide a warning signal should the water level exceed a predetermined level to contact the electrodes.

Abstract: A disposable fluid level sensor of the present invention determines the level of fluid in a container. A flex circuit sensor is coupled to a processing module having a power supply, the flex circuit sensor being mounted at a selectable location by an adhesive patch which holds the sensor flush against the container. The processing module hangs from the flex circuit, and provides a human perceptible indication, such as a flashing light or an audible alarm, when the fluid level drops below a desired point as determined by the sensor. The sensor detects the change in fluid level by transmitting an electromagnetic signal and determining whether there is a change in reflected energy.