Abstract: An automatic sub-floor pumping system, having a controller box, sensor wires, suction hose and pump. Two or three sensor probes are used--the lowest, or ground, probe can be omitted, and the circuit referenced to earth or wiring ground. The pump evacuates water from beneath the basement floor through a hose inserted into a small hole drilled into the basement floor. The sensor probes can be simply wires with the last 1/8" to 1/2" bared, attached to the outside of the pump suction hose at two locations an inch or two apart. The hose, with wires attached, is inserted down the one-inch evacuation hole bored through the floor. The control uses a very low current on the wires, which are negative relative to ground so as to be cathodically protected from corrosion. An optional sensing circuit monitors lower probe wire voltage and warns of possible corrosion effects.

Abstract: A sensor assembly for measuring characteristics of motor oil in a vehicle includes a housing adapted to be mechanically coupled to a vehicle for receiving motor oil of the vehicle and at least one capacitive sensor including sensing electrodes positioned relative to the housing to measure characteristics of motor oil between the sensing electrodes. The sensing electrodes are coated with a soot build-up inhibiting coating which, in a preferred embodiment, is a silicone coating. The at least one capacitive sensor include an oil level sensor and an oil deterioration sensor in a preferred embodiment.

Abstract: A sensor assembly includes a tilt sensor, an oil level sensor, an oil temperature sensor and an oil deterioration sensor, as well as associated output signal conditioning electronics integrated within a common assembly. The sensor assembly is configured to receive a volume of motor oil proportional to a total volume of oil in an engine. The oil level sensor, oil temperature sensor and oil deterioration sensors include electrodes which are completely or partially immersed in the volume of motor oil depending upon the total volume of oil in the engine. The tilt sensor includes only two electrodes both of which are at least partially immersed within a controlled volume of dielectric fluid which is physically and electrically isolated from the volume of motor oil. One of the electrodes of the tilt sensor is completely immersed in the controlled volume of dielectric fluid independent of an angle of the tilt sensor relative to a vector representing forces such as gravity applied to the tilt sensor.

Abstract: A modular overfill alarm assembly is constructed and arranged to be installed in-line with a vent pipe in a vented storage tank for liquids such as waste oil or gasoline. The alarm assembly includes a vent tube having an open lower end that is threaded to be mounted to a vent opening in a vented storage tank, and an open upper end that is threaded to have a vent pipe mounted thereto, so that the vent pipe may be communicated with the vent opening as it would if it were threaded directly into the opening. The assembly further includes a support bracket mounted to the vent pipe and vent tube for supporting a commercially available alarm for actuating the alarm.

Abstract: The invention includes a system for monitoring the performance of an automatic dosing siphon utilized in reservoir which is a part of a wastewater treatment system. The siphon includes a bell type cover, a fluid trap having one leg extending upward into the bell, and an outlet discharge pipe connected to said trap. A flow detect switch is located in the discharge pipe. Upon siphon activation the switch is opened and a countdown timer is reset. After draining the reservoir, the switch closes and the timer starts counting down a predetermined time period. If the siphon doesn't activate, time expires and an alarm is triggered. A second system utilizes a solenoid drain valve located above the outlet portion of the siphon trap such that upon time expiring the valve opens, the tank drains, and the timer resets. The valve automatically reprimes the siphon. The system continues to monitor the siphon and initiates an alarm upon subsequent siphon failures.

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 steam generator with automatic supply having a level sensor arranged in a zone of a vessel located at a set threshold level, the sensor measuring the temperature and comparing it with a reference temperature, in order to establish whether a liquid reaches the threshold level, and an adjustment means acting in relation to the steam tapping operations so that the sensor temperature varies in relation to the level of liquid over a variation range, wherein the reference temperature remains within the variation range.

Abstract: A water appliance detection and cut off apparatus is provided including a water entry conduit for receiving water from a water source. A pan is provided having a bottom face and a lip coupled thereto and extending upwardly therefrom for defining an open top and an interior space into which the water appliance is stored. A water ball valve is connected to the water entry conduit. In use, the ball valve has a closed orientation upon at least the instantaneous receipt of an activation signal wherein water is prevented from flowing to the water appliance and an open orientation upon at least the instantaneous receipt of a deactivation signal wherein water is allowed to flow to the water appliance.

Abstract: A universal read head for a tank-level float gauge is adapted for use with any of certain different types of gauge rods which may be connected to a float element in the tank, including rods having an optical code thereon including a plurality of alternating reflecting and non-reflecting stripes arranged between magnetic end portions, and a rod with one or more magnets disposed adjacent to each end thereof and longitudinally spaced magnets intermediate the ends. The sensing head includes an LED light source for illuminating the rod and two phototransistors coupled in quadrature relationship for detecting the illuminated optical code patterns, and two magnetic reed switches for sensing the proximity of magnets on the gauge rod. The sensors are coupled to a microprocessor for interpreting the electrical signals generated by the sensors to identify the type of gauge rod being used and to provide an indication of the position of the gauge rod relative to the sensors.

Abstract: A new HOT WATER HEATER LEAK PROTECTION SYSTEM for PREVENTING OVERFLOW OF HOT WATER IN IF A HOT WATER HEATER BREAKS. The inventive device includes an overflow tank having a cylindrical stand positioned centrally thereon for positioning a hot water heater thereon. The overflow tank has a supplemental housing secured therein. The supplemental housing has an opening in a lower portion thereof to allow water to flow therethrough. An automatic float switch is positioned within the supplemental housing. A pump is disposed within the supplemental housing. The pump is in communication with the automatic float switch. A shut off valve is disposed within a housing coupled to a water line leading into the hot water heater. The shut off valve is in communication with the pump and the automatic float switch.

Abstract: Alarms for testing sensors, particularly those used in fire-suppression systems, are described. In one aspect of the invention, the alarm includes an audio and/or a visual indicator operably coupled to the housing of a sensor. The audio indicator may be a speaker that beeps when the sensor is activated. The visual indicator may be one or more LEDs that are illuminated when the sensor is activated. The alarm also can be used to determine whether power and ground conductors extending to the sensor are properly connected. Additionally, the alarm can be used to determine whether one or more conductors extending from the sensor to the control panel are properly connected.

Abstract: A pump control system which can distinguish between water and oil so that a pump can be controlled to pump water and deactivated before oil is pumped. Sensing is accomplished by a pair of capacitive sensors, one located above the other in a vessel in which water accumulates. A dual mode frequency oscillator is associated with each sensor. Each sensor reacts to the dielectric constant of the liquid at the sensor by changing its capacitance, to thus detect the presence of a conductive substance, such as a liquid, to cause the sensor's oscillator to switch its mode of oscillation. The dual mode oscillator of each sensor selectively generates a control signal having two different duty cycles. As the dielectric constant of the liquid medium is sensed, a logic circuit interposed between the sensors allows the output of each sensor to be turned off when only the lower sensor is in water. The circuit turns on the pump only when both sensors are in water and the pump remains on until both sensors are out of water.

Abstract: A liquid level detector utilizing a housing having a wall portion defining a inner chamber. The inner chamber communicates to the exterior of the housing through an opening which also permits liquid to enter the chamber. A floatation element is pivotally located within the housing and includes a bridging conductor which rotates upwardly. The bridging conductor is capable of contacting a pair of terminals which constitute a portion of an alarm circuit.

Abstract: A level detector circuit for detecting a level of immersion of an elongated probe within a liquid. The level detection circuit includes a first set of transistors. One of these transistors charges an elongated probe and a second charges a capacitor. A reference current source provides a reference current based on the charging current provided to the elongated probe by the first transistor and an additional transistor which also charges the probe at a rate such that the voltage on the capacitor and the probe are maintained the same. A monitoring circuit develops an analog level signal based on the current provided by the reference current source. This analog level signal is converted by the combination of an analog to digital circuit and a microprocessor for providing a pulse frequency modulated communications signal corresponding to the analog level signal which in turn is related to the length of the probe immersed within the liquid.

Abstract: A low water level indicator includes a detection assembly and an indicator unit. The detection assembly comprises a housing, a pair of electrodes, a control unit, and a battery. The indicator unit comprises a light emitting diode (LED) and a base plate. The housing is preferably molded as two halves which are joined at assembly. An adjustment rod is held by a first and second snap retainer at substantially the bottom of the housing. The adjustment rod is used to adjust the height of the bottom of the housing relative to a water container. The electronic control circuit is mounted in a top cavity. A hook rod is held by a top spring clip which is disposed at substantially the top of the housing. The hook rod is used to provide stability for the placement of the detection assembly. When the water level in a water container is too low, electrical current will no longer pass from the first electrode to the second electrode through the water.

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: An automated waste cooking grease recycling tank having a top, a bottom, at least one side wall defining an inside and an outside of the tank with a plurality of openings in the tank. A liquid level sensor is inserted into the inside of the tank through one of the plurality of openings with the liquid level sensor operatively connected for sensing at least first and second different liquid levels inside of the tank. A control panel is positioned outside of the tank, operatively coupled to the level sensor and having first and second indicators thereon responsive to signal the first and second different liquid levels sensed inside of the tank. A fill pump is operatively coupled to the control panel and responsive to the control panel for adding grease.

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: An improved cut plant watering apparatus for detecting and indicating a predetermined water fill level to prevent overfilling and spillage when watering a cut plant, such as a Christmas tree, mounted in a container comprising a conduit for carrying water from a fill location to the container, an indicator in communication with and responsive to a detector that, when used to fill the container with water, indicates that the predetermined water level has been reached so that a person does not inadvertently overfill the container, thereby eliminating water damage to surrounding objects or to the carpet and floor.

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: 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 flow alarm includes a magnetic switch that is maintained open so long as catalyst flow is maintained and an air flow switch that is closed responsive to flow of air through an associated conduit. The associated conduit supplies air via a solenoid valve to a pneumatic whistle. When flow of catalyst falls below a pre-set threshhold, the magnetic switch closes completing the circuit with the solenoid valve causing the solenoid valve to open and allowing air flow to the pneumatic whistle to signal the reduction of catalyst flow.

Abstract: The present invention is a water level detector or flood alarm device which will activate a warning once water has reached a pre-determined and potentially damaging or dangerous level. The present invention comprises a housing which maintains a conventional mercury activated float switch, an alarm coupled to the switch, a mounting device, and an attaching mechanism. The mounting device maintains the housing and includes a pivotal mechanism for enabling the housing to pivot and rotate. This pivoting and rotation will allow the housing to be angularly positioned, with respect to the ground, so that the float switch will be positioned horizontally and parallel with respect to the water. The attaching mechanism enables the device to be removably secured to any surface and to be maintained in a secured and installed position.

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: A device and method for sensing fluid characteristics, including level, temperature, pH and chemistry, comprises a switch affixed to or embedded in a container of a size, shape and density such that said container floats stably in said liquid until a predetermined level is reached; the container tilts so as to operate the switch when the liquid drops below or increases above a predetermined level. The device may contain additional sensors which measure and report other characteristics of the liquid, such as temperature, pH, viscosity, chemistry or biochemistry.

Abstract: An apparatus and method for the cordless remote control of a filling function of a mobile vehicle that includes a signal transmitter (12) and a liquid level sensor (14) that is mounted on a tank (18) of a mobile vehicle (16). The liquid level sensor (14) transmits a full signal to a remote signal receiver (22) by way of the signal transmitter (12). The full signal closes a control valve (26) interupting the flow of the fluid to the tank (18) by way of a conduit 28. An adjustable timer (44) provides a system safety back-up signal that closes the valve (26) if the full signal is not received within a preset time period. This apparatus and method can be operated in a semi-automatic mode or an automatic mode by the addition of an adjustable delay clock/timer (42). Audible and/or visual indicators are provided for monitoring the status of the filling operation.

Abstract: For monitoring a predetermined level of a liquid in a container an ultrasonic transducer is fitted on the outer surface of the container wall at a measurement point situated at the height of the level to be monitored. The ultrasonic transducer when excited by an alternating voltage pulse having a given transmission frequency which equals the thickness resonant frequency of the container wall, transfers an ultrasonic transmission pulse to the container wall and converts ultrasonic vibrations, generated by reflected echo pulses, into electrical reception signals that are transferred to an evaluation circuit. In the evaluation circuit, on the one hand the presence or absence of echo signals is detected, and, on the other, the ultrasonic vibrations generated by the after-vibration of the container wall at the end of the transmission pulse are evaluated.

Abstract: For monitoring a predetermined level of a liquid in a container an ultrasonic transducer is fitted on the outer surface of the container wall at a measurement point situated at the height of the level to be monitored. The ultrasonic transducer contains a piezoelectric element which generates, when excited by an alternating voltage pulse having a given transmission frequency, an ultrasonic transmission pulse which is transferred via a diaphragm to the container wall and which converts ultrasonic vibrations transferred from the container wall to the ultrasonic transducer into electrical reception signals. The diaphragm comprises on the side facing the container wall protuberances which adjoin the container wall. Between the diaphragm and the container wall a coupling layer is arranged, the thickness of which is determined by the height of the protuberances.

Abstract: A ground water alert device includes an elongated water proof cable member which has a predetermined length and is inserted into a water level monitoring pipe of a well for a predetermined depth above a water table, a cable housing for delivering and collecting the cable member, a water sensor such as a probe which is electrically connected to a free end of the cable member for lowering into the monitoring pipe to the predetermined depth above the water table, a DC power source, a control circuitry electrically connected between the DC power source and the cable member for generating alert signals when the water sensor detects water, a depth indicator having a plurality of length scales uniformly provided along the cable member to indicate the length of the cable member from the water sensor, and a cable supporter for securing the cable member in place at a top end of the monitoring pipe so as to ensure the predetermined length of the cable member retaining in the monitoring pipe.

Abstract: A liquid level detecting system for detecting a conducting liquid level in a non conductive container which utilizes a grounding rod mounted in a lower portion of the container and a conductive sensing rod mounted at a position above the grounding rod. An oscillator is provided having a frequency in the range of about 600 hertz to about 100 kilohertz. The output of the oscillator is applied to the sensing rod through a high impedance circuit and a high pass filter. In another embodiment, the high pass filter may have the higher end frequencies attenuated to produce a band pass filter which selectively passes the frequency of the oscillator. The voltage drop across the circuit which includes the conductive sensing rod to ground is detected by a voltage peak detector and a threshold detector to produce an output which detects the drops in voltage when the conductive fluid level in the tank rises so that both the sensing rod and the grounding rod are covered, completing the circuit.

Abstract: The device for determining and/or monitoring a predetermined level of contents in a container comprises a sensor, which is so mounted on the container at the level of contents to be monitored that it comes into contact with the contents of the container when the same reach the predetermined level. The sensor is excited to mechanical vibrations at its natural resonant frequency by an exciting arrangement. An evaluating circuit serves for causing indicating and/or switching operations in a manner dependent on whether the frequency of the mechanical vibrations of the sensor is higher or lower than a switching frequency. Associated with the sensor is an electrical circuit element which has a characteristic parameter, whose value bears an unambiguous relationship to the natural resonant frequency of the sensor. In the evaluating circuit the switching frequency is set in accordance with the value of the characteristic parameter of the electrical circuit element.

Abstract: Disclosed is a method of detecting the clogging of a filter installed in a washing machine by which a user can recognize the clogging of the filter. The method comprises the steps of detecting a first frequency using a liquid level sensor when a liquid level in an outer tub has reached a first liquid level, of recording a value of the first frequency in a memory section of the microcomputer, of demoting a second frequency using the liquid level sensor when a liquid level in the outer tub has reached a second liquid level which is formed in the outer tub while the washing cycle is being executed, of recording a value of the second frequency in the memory section of the microcomputer, of calculating a value of a third frequency by subtracting the value of the first frequency from the value of the second frequency, and of sending an operating signal to a signal lamp when the value of the third frequency is lower than a predetermined frequency range which is preset in the microcomputer.

Abstract: The present invention relates to a wireless remote fuel gauge (10) comprising a tank gauge (12) positioned on a fuel tank (16A, 16B). The tank gauge (12) comprises a tank gauge microprocessor/analog converter (12A) electrically connected to a tank gauge power line (12F). A tank gauge transmitter (12B) is electrically connected to the tank gauge microprocessor/analog converter (12A). The tank gauge transmitter (12B) functions to transmit, by radio frequency, a level of fuel (18) information within the fuel tank (16A, 16B). A tank gauge indicator (12D) is mechanically connected to the tank gauge microprocessor/analog converter (12A). The tank gauge indicator (12D) functions to allow a consumer to visually monitor the level of fuel (18) within the fuel tank (16A, 16B). The tank gauge float (12G) maintains position on the level of fuel (18) within the fuel tank (16A, 16B).

Abstract: Abnormal flow of liquid in a non-pressurized conduit such as a drain line of a building is detected by a liquid level sensor unit connected at a conduit location not anticipated to fill with liquid during normal flow, so that liquid backing up at such location will enter a sensor chamber of the unit to cause a liquid level sensor to signal an indicator. A monitoring system uses at least one such sensor to signal at least one local or remote indicator that indicates which sensor has detected abnormal flow. The system can monitor for short times particular drain lines suspected of experiencing abnormal flow, or can serve on a long-term basis to provide an early warning of clogging and blockage in lines selected for monitoring.

Abstract: Disclosure is made in this application of a pedestal housing and a pedestal control housing segment mounted at the top of the pedestal housing and a control panel board mounted in the control housing segment and power lines entering the pedestal housing below the ground level and into the pedestal housing and lead connectors extending from sump pump and sump pump float switch and tank alert float switch extending from sump tank through a connector duct or pipe into the pedestal housing and extending to the control panel board in the housing segment and a door mounted on the control housing segment to seal the control housing segment. The lead connectors of the power lines and the float switches extend through apertures in the bottom of the control housing segment and are held in position by grommets to seal the openings around the lead connections.

Abstract: A level measuring device using microwaves comprises an antenna for sending transmitted waves toward the surface of a material whose level is to be measured, and for the reception of echo waves resulting from reflection at the surface, and a receiving and evaluating circuit which derives from the echo waves received by the antenna an echo function representative of the echo amplitudes as a function of the distance and determines from the echo function the transit time of the microwaves from the antenna to the surface of the material and therefrom the distance of the surface of the material from the antenna.

Abstract: A water purifier includes filters and a storage tank for storing water purified by the filters. A water detector disposed below the tank detects water leaked from the tank and supplies a corresponding signal to a control mechanism which shuts off the water flow through the purifier, displays a visual indication of leakage, and sounds an audible alarm.

Abstract: A two-terminal integrated circuit magnetic-field detector, for use in detecting a low level of a liquid in a vehicle, has a Hall element, a Schmitt type comparator, an anti-sloshing accumulator such as an up-down counter, and a latching driver all connected in tandem. The anti-sloshing accumulator is for producing a signal that is the integral as a function of time of the binary comparator output signal. During sloshing, when the average liquid level is near that at which a low-level warning signal is desired, the accumulator signal climbs in a vacillating manner. The latching driver is connected across the two integrated circuit (I.C.) terminals and latches on when the accumulator signal reaches a predetermined value, dropping the impedance across the two I.C terminals. A liquid level indicating lamp is connected in series with a source of DC voltage and the two I.C. terminals, so that when the average position of the floating magnet approaches that of the I.C.

Abstract: A method for determining a stopped flow condition in a fluid fraction measuring apparatus includes the steps of establishing a minimum threshold level of statistical variation in the measured parameter repetitively (continuously) monitored by the measuring apparatus, and giving an indication when the standard deviation, statistical average, or the kurtosis of the measured parameter or characteristic drops to the threshold level.

Abstract: Apparatus and method for determining when the depth of molten (18) poured into a vessel (12) has reached a selected level. A conduit (22) connected to a source of pressurized gas and having an orifice (43) at its distal end (38) restricts the flow of gas out of the conduit which is positioned at a selected level in the vessel. A drop in pressure in the conduit (22) resulting from escape of compressed gas when the distal end (38) is melted by the rising molten metal is detected and signalled to a visible, audible indicator or directly to an electronic controller to discontinue pouring of metal (18) into the vessel (12).

Abstract: A bath overflow alarm comprised of a housing having a pair of slots formed through a lower end thereof. The housing has a waterproof battery chamber therein for active receipt of a battery. The housing is adapted for securement to a bathtub. A pair of water contacts are secured within the housing. An alarm mechanism is secured within the housing disposed above the pair of water contacts. Once water enters into the housing through the slots, the water contacts signal the alarm mechanism which will alert a person as to a dangerous water level.

Abstract: Apparatus for indicating material level that includes a pair of ultrasonic transducers on opposed sides of a space for receiving the material at the level to be detected. A swept frequency oscillator is coupled to one of the transducers so that the transducer radiates into the material space ultrasonic energy that continuously sweeps back and forth between a low frequency range at which such energy is transmitted to the other transducer by resonance of the entire apparatus and independent of presence of material in the material space, and a higher frequency range at which such energy is transmitted to the other transducer only when material is present in the space between the transducers. Detection circuitry indicates presence of material between the transducers upon receipt of the higher frequency energy, and failure of the apparatus upon failure to receive the lower frequency energy.

Abstract: A sensor system is operable for detecting the presence of water in an oil emulsion inside the lower gear unit of a marine engine, and for providing an alarm signal when the presence of water is detected within the gear unit. The sensor system includes a ring oscillator circuit and a symmetrical array of passive input probes which are disposed in the oil/water emulsion inside the oil chamber. Each of the passive input probes is electrically connected to the ring oscillator circuit wherein the probes function as fixed capacitors for measuring the electrical characteristics of the emulsion. When a voltage is applied to the oscillator circuit, the oscillator circuit generates an oscillating signal that circulates at a frequency which varies according to the dielectric-properties of the liquid emulsion. When water is introduced into the chamber, the water is emulsified with the oil thereby changing the electrical characteristics of the oil.

Abstract: A residential oil-fired furnace heating system includes an oil storage tank having a fuel level gauge, and a second fuel level indicator located in a zone remote from the fuel oil storage tank. The homeowner can read the oil level from the second indicator without having to go down into the basement or other area where the tank might be located. The second indicator can have an alarm device that is triggered when the indicator reading reaches the near-empty reading. The alarm device alerts the homeowner that it is time to reorder a new supply of fuel oil.

Abstract: A numerically controlled lathe includes a spindle, a hydraulic rotary cylinder driven by a pressurized working fluid for causing the spindle to rotate, a fluid pump for discharging the working fluid to be delivered to the hydraulic rotary cylinder, a reservoir for storage of the working fluid, first and second delivery conduits each having first and second ends, the first ends of the delivery conduits selectively connected to the fluid pump and the reservoir, and a fluid coupler for coupling the second ends of the delivery conduits with the hydraulic rotary cylinder.

Abstract: An automated liquid level sensing system for use in an automated, continuous, and random access analytical system is disclosed. A pipette probe is positioned above, and lowered into, a liquid sample container which contains the liquid to be detected. The probe is energized by a near radio-frequency (RF) signal source. A receiving antenna is positioned below the sample container, and is oriented so that very little signal is detected from the probe while the probe is in air. When the probe contacts liquid in the sample container, the electromagnetic field of the RF signal is increased and reoriented toward the receiving antenna. An autozero circuit maintains a near-zero output from the receiving antenna when slow changes in signal level occur due to changes in probe position or other environmental factors. The autozero circuit allows the sudden increase in signal amplitude, due to liquid contact, to pass to a receiver.

Abstract: A liquid level sensor device, particularly adapted for use with corrosive and hazardous liquids such as oil, for measuring the liquid level in a storage tank or vessel. A tubular device is placed vertically in a liquid storage tank and senses the liquid level by having a float embedded with magnets move vertically along the axis of reed switches encased in the tubular device. The device contains temperature sensors to measure the temperature of the tank fluid, and microprocessors that scan the reed switches, transmitting data through a connector in the device top to a nearby computer for recording and transmission to a control and monitoring location. The electrical data system inside the device utilizes only two conductive trace runs throughout the device length to maximize reliability while minimizing the copper used. Special mechanical and electrical assembly connectors inside the device permit the device to flex safely in turbulent liquid conditions, without breakage.

Abstract: In devices for determining and/or monitoring a predetermined level with a sensor that is excited to perform mechanical oscillations at its self-resonant frequency by means of an electronic excitation circuit which is excited via a piezoelectric excitation and a reception transducer and an evaluation circuit for triggering display and/or switching processes, there exists the difficulty that the natural frequencies of the sensors are different due to the manufacturing conditions, and that the operating frequency must be adjusted individually for each sensor. This disadvantage makes repair and maintenance procedures quite difficult.

Abstract: A device for warning when a low fluid level is reached is provided in which a levelness detecting switch is encapsulated in a conically shaped inert material (such as TEFLON.TM.), sized appropriately to the predetermined fluid limit, and coupled to an alarm device (such as an audible alarm, a frequency signal or a light).