Abstract: A method of determining a temperature and a pressure in a tank is provided. The method comprises the steps of obtaining sensor data and calculating coefficients. Then, a bridge resistance is ratiometrically determined from a bridge voltage. A temperature is calculated with the coefficients and the bridge resistance. Thereafter, a transition from a temperature measurement mode to a pressure measurement mode is made. A voltage per resistance is calculated with the coefficients and a differential voltage. Then, a normalized voltage is calculated using the voltage per resistance, the differential voltage, and the bridge resistance to indirectly compensating for temperature. A pressure is calculated with the coefficients and the normalized voltage.

Abstract: Fuel filter for diesel engines with high pressure direct injection of common rail type and the like, comprising an outer casing provided with a fuel inlet conduit (3) and an outlet conduit (4), and containing in its interior a filter means(5), a temperature sensor(15) being positioned in proximity to the bottom of said casing to measure the temperature of the fuel present in the casing.

Abstract: A container with functions of level, crud and temperature detections, comprises: a hollow casing having a receiving space at an upper side thereof; the casing being formed with a hollow space; a vent hole being formed at a bottom side of the casing for communicating the hollow space and exterior of the casing, an electric heating source installed in the hollow space of the casing and being tightly adhered to a wall of the hollow space below the receiving space; and a sensing and control circuit installed at a lower outer side of the casing; the sensing and control circuit including a microcontroller, an analog/digital converter, a gain amplifier, and a trigger circuit; and the wall of the casing being installed with at least one over level detection point, at least one level alarm detection point, at least one safety level detection point, at least one liquid temperature detection point, and at least one crud detection point.

Abstract: A process for monitoring a fluid storage system using a vessel for storing the fluid and a detection apparatus using synchronized sensors for monitoring and measuring state properties of the fluid is disclosed. The method includes using a housing with at least one pressure sensor and at least one temperature sensor for synchronously collecting data regarding the fluid. Each sensor communicates with a processor and a signaling means to provide synchronized data. The method includes continuously forming at least one calculated value, such as a value for mass of the fluid, from the data synchronously collected using a processor, and continuously comparing the calculated value to at least one predetermined range of values for the fluid in the vessel to identify if the at least one calculated value is within the predetermined range of values. Then, the method includes communicating the compared values from the processor to an auxiliary device.

Abstract: A radar level gauge system, for determining a filling level of a product contained in a tank, the radar level gauge system comprising a transceiver including a signal generator for generating electromagnetic signals for transmission; a transmitter branch for transmitting the electromagnetic signals; and a receiver branch for receiving electromagnetic signals.

Abstract: A radar level gauge system, for determining a filling level of a product contained in a tank, the radar level gauge system comprising a transceiver including a signal generator for generating electromagnetic signals for transmission; a transmitter branch for transmitting the electromagnetic signals; and a receiver branch for receiving electromagnetic signals, the transmitter branch and the receiver branch each being connected to a transceiver input/output terminal.

Abstract: A level detection module is capable of detecting level of liquid in a container and includes the first induction unit, the second induction unit and a detection unit. The first and second induction units are disposed at the first position and second position of the container respectively and output the first and second induction signals respectively according to change of temperature. The detection unit provides a controller with input ends corresponding to the induction units and at least an output end. The controller compares the difference between the first and second induction signals and outputs a control signal, which stands for the liquid reaches to the preset position, based on difference of the signals via the output end. Due to temperature of the liquid at the bottom of the container being different from the room temperature of the air at the top of the container, the level of the liquid is measured with the principle of the difference of temperature.

Abstract: The present invention deals with determining the level of fluid in a container. Typically, a beverage container containing a liquid will absorb heat energy from the surrounding environment at a greater rate than a gaseous component in the headspace of the beverage container. Thus, as the liquid is drawn from a beverage container a greater headspace results. If a thermometric measuring device is employed along the height of the beverage container the volume may be determined by observing the difference in the temperature along the height of the beverage container. In practice, a beer keg may exhibit a difference of as much as 9° Fahrenheit on the exterior surface of the beer keg when measured at the headspace as opposed to the area where the liquid is present in the beverage container.

Abstract: A detection apparatus for use in a vessel for measuring a fluid includes a tubular connected to a housing containing sensors, wherein the housing includes a top, a bottom, and a hole disposed in the top of the housing. The housing containing sensors includes an outer surface and a sloped inner surface sloping from the outer surface toward a central axis of the housing and intersecting with the hole. In one embodiment, two or more housing containing sensors can be included with detection apparatus. A pressure sensor, having a diaphragm flush mounted in the sloped inner surface, can be disposed in the hole. Signaling device can be disposed in the hole for communications between the sensors and a processor. The processor receives data from the sensors and converts the data to values for transmission to an auxiliary device.

Abstract: A device for measuring at least one of a level and a temperature of a liquid in a container includes a resistor arrangement adapted to be immersed in the liquid. An immersed length of the resistor arrangement in the liquid corresponds to the level of the liquid in the container. The resistor arrangement includes upper, middle and lower temperature-dependent elongated resistor elements connected in series or in parallel. Each resistor element has an uniform resistance per unit length along a length thereof. The upper and lower resistor elements are shorter than the middle resistor element. A power source is connectable to the resistor arrangement. Voltage drops across or currents flowing through the resistor elements are measured. A microprocessor is arranged to calculate the immersed length of the resistor arrangement or the temperature of the liquid from predetermined lengths of the resistor elements and from the measured voltages or currents.

Abstract: A temperature and pressure measuring circuit is provided. The circuit comprises an uncompensated pressure transducer, an analog-to-digital converter, a reference resistive device, and first and second switches. The transducer has variable resistive devices between first, second, third, and fourth bridge nodes. The analog-to-digital converter has first and second reference inputs and first and second differential inputs. When the first switch couples the first differential input and the third bridge node and the second switch couples the second differential input and a ground, a bridge voltage is measurable and a bridge resistance is ratiometrically determinable. The bridge resistance is employed to calculate a temperature. When the first switch couples the first differential input and the first bridge node and the second switch couples the second differential input and the second bridge node, a differential voltage is measurable. The differential voltage is employed to calculate a pressure.

Abstract: A level detector for storage tanks for fluids comprises a microprocessor, a network of resistive elements connected in series or parallel, and a plurality of conductive elements between them, connected across a power source. The resistive elements have a high temperature coefficient, and are heated by passing a high electric current through them, after which a low electric current is passed through them and the voltage between them is sampled by the microprocessor. The resistive elements lose heat through conduction, so that a pair of resistive elements can be detected having differential cooling between them as a consequence of being adjacent to the void within the tank or the fluid within the tank. Thus, an approximation of the fluid level within the storage tank can be determined and signalled remotely.

Abstract: The present invention deals with determining the level of fluid in a container. Typically, a beverage container containing a liquid will absorb heat energy from the surrounding environment at a greater rate than a gaseous component in the headspace of the beverage container. Thus, as the liquid is drawn from a beverage container a greater headspace results. If a thermometric measuring device is employed along the height of the beverage container the volume may be determined by observing the difference in the temperature along the height of the beverage container. In practice, a beer keg may exhibit a difference of as much as 9 degrees Fahrenheit on the exterior surface of the beer keg when measured at the headspace as opposed to the area where the liquid is present in the beverage container.

Abstract: According to an exemplary embodiment, the present technique relates to a fuel sensor for determining operational fuel level (hnew) in a fuel tank (14). In the exemplary embodiment, an isolated airspace (44) is created. By monitoring the pressure conditions in the isolated airspace 44 as well as the pressure and temperature conditions in the remainder (42) of the tank (14), the operational fuel level (hnew) may be determined.

Abstract: A low-water cut-off system [A] determines if fluid [W] within a boiler [16] or other enclosure drops below a predetermined level within the enclosure. A signal generator introduces a signal into the enclosure so that the signal is present for sensing at the predetermined level, where a probe [14] is provided for sensing the signal if present as occurs if the water is at the predetermined level. A control [18], which includes a microcontroller [25], is responsive to the probe for providing a control function in response to whether the signal is so sensed by the probe, and so to determine if water has dropped below the predetermined level. The function may be causing alarm signalling or boiler heating cut-off. Self-test and time delay features are also included. Provision is made so that the control compensates for variation in electrical conductivity of the water through which the probe signal is sent.

Abstract: A fuel tank interface assembly is provided. The assembly provides interface and control to a plurality of different types of components. Some of the components may be situated inside the tank. A connector is sealingly mounted through a single opening in the tank and is configured to provide at least two electrical leads for each different type of component in the tank. A unitary control unit is electrically coupled to the connector and is configured to provide control to each of the plurality of different type of components through the at least two electrical leads.

Abstract: An apparatus operable in a wet environment for detecting the presence or absence of water in a non-conductive vessel, by measuring changes in dielectric constant and detecting the temperature of water in same vessel. A conductive element coupled to a sensing and switching means, transmits data to the controller, resulting from a change of dielectric constant at the conductive element. A temperature sensor detects and transmits temperature signals to the controller. A controller means receives data, from the dielectric constant sensor means and temperature data from the temperature sensor. Includes a coupling means which transmits data from the controller to an external device. The isolation means electrically isolates the conductive element and temperature sensor means from the water contained in a non-conductive vessel.

Abstract: A new high precision volume gauging system for measuring the volume of a propellant VL enclosed at a first pressure PU within a propellant tank (40) of a volume VT. The improved precision compared with prior art is achieved in that it comprises a high precision pressure sensor (90) which is comprised of a reference chamber (115) that is connected to the propellant tank (40) by a communication line (140), a valve (150) for controlling the gas flow through the line (140), and a high precision differential pressure sensor (95) that is arranged to record the pressure difference between the reference chamber (115) and the propellant tank (40) to which it is connected through a communication line (130).

Abstract: A remote two-module electronic fluid monitoring system. A tank module sits atop a field tank and monitors internal fluid level. Fluid level detection is achieved by tracking the position of an embedded permanent magnet associated with a given internal fluid level within an existing float gauge mechanism. An integrated circuit capable of precisely detecting the orientation of magnetic fields senses the angular position of an existing magnet and outputs an angular field reading to an interfaced microcontroller which then translates angular reading to fluid level. The tank module contains a radio frequency transmitter which then sends fluid level information to a display module. The display module receives the signal from the tank module and reports to the user the present fluid level remaining in the tank via a liquid crystal display.

Abstract: A monitor for remote reading of liquid volumes in pressurized tanks utilizes a hollow buoyant displacement probe extending downwardly from a load cell carried adjacent a top port in the tank. The buoyant probe is optionally formed in detachable segments so that it can be assembled on site at the time of installation. The load cell is suspended from a flange cover acting as a closure for the tank port so that the load cell is freely pivotable on perpendicular horizontal axes, insuring that it is always oriented horizontally. A temperature-reading string is positioned in the open hollow center of the probe and has three spaced temperature sensing units along its length.

Abstract: In a device for measuring the filling level, thermoelements (20) are used which are disposed on a sheet-shaped support (25). The thermoelements (20) consist of two different materials and are disposed in two rows (71, 72) placed side by side. Two adjacent thermoelements (20) of said rows (71, 72) have a common junction point (23) that is heated. Both rows (71, 72) of thermoelements also have two additional junction points that are cold. A first group of thermoelements (20) is disposed with their supports (25) in the interior of the container and operate as measuring detectors. A second group of thermoelements (20) serves as reference sensors since they regulate the heat flow impinging upon the junctions points (23) relative to a defined reference voltage.

Abstract: The present invention relates to a pressure housing for in-water pressure based systems and to a method for improving the life of the transducers and electronics of underwater systems by maintaining a humidity-free and clean environment around them by avoiding the entry of humidity, dust, or any suspended particles in the air during occasional data offloading and battery replacement in a humid and dust-laden field station; improving the ease of closing and opening of the pressure housing by the use of a novel arrangement thereby avoiding the use of conventionally employed cumbersome protruding and corrosion-prone locking devices such as screws, bolts, or clamps; and implementing reliable transmission of water pressure to the pressure port of the transducer, simultaneously minimizing the errors arising from dynamic pressure effects, preventing its chemical corrosion from saline water, and arresting bio-fouling in the vicinity of the pressure inlet.

Abstract: A measuring device for calculating the depth of a liquid in a container comprises a dipstick, a plurality of indicia on the dipstick and a thermometer on the elongate member which measures the temperature of the liquid in the container such that the temperature and depth of the liquid is measured. A method of measuring liquid providing an elongate member inserted within a container of liquid such that the elongate member engages a bottom surface of the container. Providing a temperature sensor on the elongate member such that the temperature sensor is submerged in the liquid and reading the temperature of the liquid on a display which displays the temperature sensed by the temperature sensor. Removing the elongate member from the container, locating an imprint from the liquid and reading the level of liquid in the container on a plurality of indicia on the elongate member.

Abstract: A lightweight elongate flexible temperature probe includes several temperature sensors embedded inside multiple layers of a thin film polyimide or polyester in which two of the layers are thin film copper etched to form conductors to the sensors. The conductors are in abutting electrical contact with the sensors.

Abstract: A water-monitoring apparatus includes a frame installed by water. A reel is mounted on the frame. A cable including lower and upper ends is wound on the reel. A buoy is connected with the cable. At least one sensor is used to detect a water quality parameter and to produce a signal representative of the water quality parameter. The at least one sensor is carried via the buoy and electrically connected with the lower end of the cable. The reel can be rotated to adjust a length of the cable extending from the reel so that the at least one sensor can always be immersed in the water. A signal relay includes a first block electrically connected with the at least one sensor and a second block electrically connected with a monitoring station wherein the first and second blocks are connected with each other in a non-contact electric manner.

Abstract: An apparatus operable in a wet environment for detecting the presence or absence of water in a non-conductive vessel, by measuring changes in dielectric constant and detecting the temperature of water in same vessel. A conductive element coupled to a sensing and switching means, transmits data to the controller, resulting from a change of dielectric constant at the conductive element. A temperature sensor detects and transmits temperature signals to the controller. A controller means receives data, from the dielectric constant sensor means and temperature data from the temperature sensor. Includes a coupling means which transmits data from the controller to an external device. The isolation means electrically isolates the conductive element and temperature sensor means from the water contained in a non-conductive vessel.

Abstract: A sensor for determining the location of the surface of liquid in a container, includes: a hollow tubular stainless steel probe inserted into said container, said probe having one portion arranged above the surface of the liquid and having another portion submerged in the liquid; a first thermocouple operatively arranged within the probe to sense the temperature above the liquid surface; a second thermocouple operatively arranged within the probe to sense the temperature of said liquid at a point beneath the liquid surface; a resistance wire operatively arranged within the probe; a current source operatively arranged to apply a constant-current to the ends of the wire; and an ohmmeter for measuring the electrical resistance of the wire according to the equation: RT=ƒ[kaTaHh+kwTwH(1−h)] where RT is the resistance of the wire, ƒ is the symbol for “a function of”, ka is a constant for the probe first portion, Ta is the temperature sensed by the first temperatur

Abstract: A liquid sensor has comb-shaped electrodes, applied to a piezoelectric substrate, as interdigital transducers for generating an electroacoustic wave from a transmitting transducer to a receiving transducer. The number of finger pairs of the interdigital transducers and the material out of which the electrodes are made are so chosen that a surface shear wave generated by the transmitting transducer and a bulk shear wave generated by the transmitting transducer have different frequencies.

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 method of determining the moisture content in wood in which a sample of the wood being tested is first frozen with liquid nitrogen, homogenized and a test sample is placed in a Karl Fischer titration system. The test sample is placed into a solvent solution and the reagent or titrant is progressively added to the solvent solution as the presence of moisture from the wood sample is detected. Once the moisture has been titrated from the solution the moisture content of the wood is determined based upon the amount of reagent dispensed into the titration solution.

Abstract: A method for measuring temperature and electrolyte level of a molten electrolysis bath in a cell for production of aluminum by electrolysis of alumina includes the steps of: (a) piercing the crust of a solidified bath with a crust breaker and immersing into the electrolyte, an extremity of a temperature probe to a sufficient depth until an initial temperature reading of at least 850.degree. C.

Abstract: A magnetostrictive liquid level probe in a double-walled liquid container develops liquid level data and external sensors in the space between the walls respond to the presence of liquid leaked into the space from inside or outside the container. Other sensors external of the liquid level probe may sense other conditions. The probe electronics determines binary states of the external sensors and digitally encodes the states for inclusion in data transmission of the liquid level information to a remote controller via a two-wire transmission line. One embodiment develops pulses spaced as a digital function of the sensor states and includes liquid level data between the pulses for transmission. The pulse space is measured at the remote controller and decoded to determine the external sensor states, while the liquid level data is analyzed to determine the contents of the container.

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: The present invention is directed to a combination of a thermostat, especially for controlling the heating of a dwelling, and a level indicator for displaying the level of liquid fuel (such as home heating oil) in a storage tank that is burned for heating the dwelling and that is controlled by the thermostat. The invention is especially useful for the elderly or infirm in a wheel chair who may not be able physically to view the level indicator at the fuel tank if it is down at the bottom of the cellar stairs. In addition to a level display at the dwelling thermostat, the level indication can be accessed remotely (such as via modem and personal computer).

Abstract: The invention relates to a depth gauge for use in angling or sports fishery. The depth of a body of water may be measured therewith from its surface to its bottom, and/or the depth and the size of strata of water of different temperatures for the purpose of offering bait to different species of fish in their preferred environments, for instance at the bottom of a water or at a thermocline stratum. In accordance with the invention, a water-proof housing a temperature sensor, a pressure sensor, a digital evaluation circuit, a display and a program switch are provided within a water-proof housing and electrically interconnected in such a manner, that the measurement value about the depth of the water to its bottom and/or water strata marked by temperature differences of more than 3.degree. Kelvin are processed and stored by the digital evaluation circuit. By means of the program switch, the stored measurement data may be called up and rendered visible in the display.

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: In one embodiment of the present invention, a method for measuring fluid level use a sensor comprising a first plate having continuous electrically conductive material and a second plate having electrically conductive material disposed in segments, the electrically conductive material of the first plate in opposition to the electrically conductive material of the second plate. The method comprises immersing the sensor in the fluid with at least one segment completely immersed in the fluid and at least one said segment completely out of the fluid. The method also includes sequentially energizing the segments. Further, the method includes detecting times of voltage transitions of a first signal at the first plate, relative to the sequential energizing of the segments, as an indication of fluid level.

Abstract: An improved flowmeter sensor for measuring the level of liquid flowing in a conduit, pipe or open channel, characterized by an initially air-filled pressure transmitting passage which affords communication between a pressure port contained in the bottom of the sensor body, and a pressure transducer contained in the sensor body. The passage includes a vertical portion communicating at its lower end with the pressure port, and a horizontal portion connected with the transducer, whereby hydraulic pressure forces liquid into the passage to compress the air therein and thereby exert on the pressure transducer a pressure corresponding to the level of liquid in the conduit. The cross-sectional area and high surface energy of the material used to form the passage prevent liquid in the passage from migrating to the pressure transducer.

Abstract: A waterproof housing encases a radio and/or a television and/or a compact disc and/or a tape cassette player and speaker or other signaling and entertainment apparatus actuated by a programmable temperature actuated control and temperature indicator. A temperature probe senses the temperature in a heated environment. The control activates the signaling and entertainment device when the temperature is within a preset temperature limit range. The housing is floatable for a spa, whirlpool, hot tub, bathtub, flotation chamber, or other heated water environment.

Abstract: A level detector for detecting a level of a liquid is provided with an elongated probe having opposed proximal and distal ends. In use, the distal end of the elongated probe is submerged beneath the level of the liquid with an unwetted length of the elongated probe located above the level of the liquid. A thermal conductor or an electrical heater is provided for maintaining a temperature difference between the proximal end of the elongated probe and the liquid so that at an intermediate location of the elongated probe, located above the level of the liquid, the temperature will be dependent upon the unwetted length of the elongated probe. A thermocouple or the like can be provided for generating a signal referable to the temperature at the intermediate location and the level of the liquid can thereby be correlated with such signal.

Abstract: A method for collecting liquid temperature data from a fuel tank id achieved by providing a thermal sensitive resistive element that produces a value proportional to the liquid's temperature, a capacitor for storing a charge representative of this value, and a resistor through which the capacitor is discharged. Circuitry and software is provided that compares the voltage across the resistor to a reference as the capacitor discharges, determines the number of clock counts for which a predetermined relationship exists between the voltage across the resistor and the reference, then consults a table to determine an absolute temperature based on this clock count.

Abstract: An apparatus for detecting the temperature of a liquid fuel stored in a tank of a vehicle includes a thermal sensitive resistor immersed in the fuel. The resistor charges a capacitor to a level indicative of the temperature of the fuel. A programmable microprocessor signals a gate to open a communication path between the capacitor and a discharge resistor, then monitors the number of clock counts that occur before the voltage across the discharge resistor drops below a reference voltage. The microprocessor uses the clock count to determine the absolute fuel temperature, which it transmits to a central vehicle computer via a multiplexed data bus system.

Abstract: A magnetostrictive liquid level probe in a double-walled liquid container develops liquid level data and external sensors in the space between the walls respond to the presence of liquid leaked into the space from inside or outside the container. Other sensors external of the liquid level probe may sense other conditions. The probe electronics determines binary states of the external sensors and digitally encodes the states for inclusion in data transmission of the liquid level information to a remote controller via a two-wire transmission line. One embodiment develops pulses spaced as a digital function of the sensor states and includes liquid level data between the pulses for transmission. The pulse space is measured at the remote controller and decoded to determine the external sensor states, while the liquid level data is analyzed to determine the contents of the container.

Abstract: A humidity sensor with an excellent water-repelling property is presented by covalently bonding a monomolecular film containing fluoroalkyl groups to the surface of a humidity sensing element, used for the sensor, via siloxane bonding. A chemically adsorbed monomolecular film containing fluoroalkyl groups is formed on the surface of a humidity sensing element via siloxane bonding after dipping and holding the element in a surface active solution such as heptadecafluorotridecyl trichlorosilane, and removing the unreacted material.

Abstract: A digital liquid level sensing apparatus for detecting variations in the dielectric of a substance being sensed. The apparatus includes a capacitive element array including a plurality of individual (i.e., segmented) input plates positioned along an axis of measurement of a fluid to be detected. The array also includes a common output plate having a length sufficient to span the entire accumulated length of the input plates. A controller sequentially applies DC excitation pulses to the input plates which cause a series of output currents to be coupled onto the output plate. The output currents are input to a current-to-voltage amplifier which generates a series of corresponding analog output voltages. The analog output voltages are then input to a peak voltage detector circuit to generate a series of peak voltage signals representative of the magnitudes of the analog output voltages.

Abstract: A fluid level detection apparatus including a support member; first and second end blocks which are slidably engageable with the support member and which each have a passageway; a seal borne by each of the end blocks and disposed in each of the passageways, and a transparent tube telescopingly received in the respective passageways, and defining a fluid passageway or chamber; the present invention disposed in fluid flowing relation relative to an object of interest.

Abstract: In one aspect of the present invention, an apparatus for measuring the height of liquid contained in a storage tank is disclosed. A tube is disposed inside the tank. A float is disposed inside the tube and is buoyed on the surface of the liquid. An ultrasonic transducer is disposed inside the tube. The ultrasonic transducer emits ultrasonic pulses toward the float, receives the reflected ultrasonic pulses, and responsively produces an echo signal. The float has a top portion and a bottom portion separated by a cylindrical portion. The bottom portion including an spherical surface which receives the ultrasonic pulses. The spherical surface has a predetermined radius which is a function of the inside diameter of the tube, the height of the cylindrical portion of the float and the outside diameter of the cylindrical portion of the float. A temperature sensor monitors the temperature of the liquid and produces a thermometric signal in response to the liquid temperature.

Abstract: Apparatus is provided to monitor fuel level in a tank or tanks, and to monitor fuel pumped from multiple dispensers; and outputs from the monitoring equipment are processed to determine unwanted loss of fuel from the tank, and to determine fuel delivered to the tank.

Abstract: An apparatus and technique for fluid level determination in automatic transmissions. The invention employs an electronic control unit in association with an automatic transmission for a vehicle, the electronic control unit receiving data corresponding to transmission oil level, transmission oil temperature, engine speed, transmission speed, and transmission selected range. Upon determining that such data satisfies certain diagnostic tests, the level of transmission fluid within the transmission is determined and adjusted or otherwise normalized to ideal test conditions. The electronic control unit compensates an oil level signal for deviations in oil temperature from an optimum test temperature, and makes further compensation for deviations in engine speed and settling time at the time that the test data is acquired. Additionally, variations in oil density as a function of oil temperature are also compensated.

Abstract: A magnetostrictive liquid level transducer equipped with a number of temperature sensitive resistors is supplied with low level power from a remote station and charges a capacitor to store power for interrogation of the level transducer. The transducer is interrogated periodically for level measurements and the capacitor is recharged between interrogations. During the recharging periods, temperature measurements are made. Thus the level and temperature related data is measured and transmitted alternately. Each measurement results in a pair of pulses having a spacing corresponding to the measured value. The transmission message comprises a plurality of frames or time periods. The first frame is blank and is used for synchronizing the receiving device with the message frames. The subsequent frames have the level and temperature related data interleaved in the message and are easily sorted by the receiving device at the remote station. The data pulses are sent on the power transmission conductors.