Abstract: A fluid leak detector mechanism having a main fluid tank, an expansion tank for receiving fluid therefrom as the fluid becomes heated and expands, and a sensing chamber operatively coupled with the main tank. A signalling mechanism signals to an operator when the level of fluid in the sensing chamber has dropped significantly to alert the operator of the presence of a leak. An oil return valve is operatively coupled between the main tank and the expansion tank and has an open position that allows fluid to flow back to the main tank from the expansion tank and a closed position that blocks oil from flowing from the expansion tank to the main tank. A temperature sensor senses the temperature of fluid. A control mechanism shifts the oil return valve to its open position when the temperature sensor detects a significant drop in fluid temperature, thereby allowing the fluid levels to be reset with changes in fluid temperature.

Abstract: Apparatus comprises a probe for measuring snow pack movement, comprising a mobile element adapted to contact and be displaced by the snow pack, a static element linked to the mobile element by linkage means and adapted to remain stationary relative to the ground, and measuring means to measure relative movement of the two elements. The mobile element comprises a wand (16; 166) adapted to be placed in contact with a snowpack and having tilt means (20(a); 20(b); 168) that permit the wand to tilt away from the vertical in response to lateral movement of the surrounding snow pack. The measuring means comprises a movement sensor (50; 170) connected to the wand that measures the resulting movement of the wand. Data relay means transmits electronic signals generated by the movement sensor to a remote data collection and storage means.

Abstract: A system for use with an electric power transmission device having oil filtration apparatus including an oil filtration unit arranged external to the electric power transmission device, a motor-driven circulation pump and at least one conduit extending between the oil filtration unit and the electric power transmission device utilizes a secondary containment enclosure for enclosing the oil filtration unit, pump and conduits. The secondary containment enclosure includes a sump reservoir to which oil gravitates upon leakage of oil from the oil filtration apparatus enclosed by the secondary containment volume, and there is associated with the sump reservoir a signal-transmitting device for transmitting a signal in response to the accumulation of oil in the sump reservoir for actuating an alarm, isolating the source of insulating oil from the circulation system and disconnecting power to the circulating pump.

Abstract: A tracking buoy including a sensor to detect the presence of hydrocarbons in a body of water and a communication system to transmit data to a remote monitoring center when the hydrocarbons are detected to indicate the direction and speed of travel of the hydrocarbons in the body of water.

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).

Abstract: Disclosed is a device used to verify the identity of a selected fluid before permitting the selected fluid to be introduced into a storage vessel containing a liquid of known specific gravity. The device includes a container constructed from connecting walls to form a chamber having an opening through which a selected fluid may be introduced; a first float switch positioned in the container for generating a first signal when contacted by a fluid having a specific gravity greater than a first predetermined amount; a second float switch positioned in the container for generating a second signal in the presence of a fluid having a specific gravity greater than a second predetermined amount, where the first predetermined amount is less than the second predetermined amount, and the second float switch is responsive to the first signal from the first float switch.

Abstract: Apparatus for detecting the presence of electrically conductive fluids, including urine and other body fluids such as exudate from wounds, includes spaced-apart electrodes (44, 46, 96, 98) covered by absorbent material (58, 106, 108, 126, 128), together with a housing (30, 86, 154) containing a signaling device (32, 152, 172, 175) which produces a palpable vibration, a sound, a light, or a radio signal when fluid in the absorbent material provides a conductive path between the electrodes. Spring contacts (50, 138, 146) on the housing provide reliable connections with the electrodes and also serve to attach the housing of the signaling device (32) to structure (12, 78) supporting the absorbent material, and may also be used to attach the absorbent material to the housing in embodiments where the housing is otherwise supported.

Abstract: A leak detector is provided for detecting and indicating a leak opening of seam in a mortar increment container or the like. This will work with porous or non-porous materials. The leak detector includes a plurality of thermistors arranged to sense selective portions of the seam, and a process circuit for receiving respective signals from the thermistors for identifying and displaying a leak condition or a no-leak condition or a bad-thermistor condition.

Abstract: An oil deterioration sensor includes a housing, a substrate with a first capacitive plate mounted within the housing, a second capacitive plate mounted to the housing close to the first capacitive plate, and a total reference capacitor which includes an external fixed reference capacitor. The second capacitive plate is mounted to the housing such that oil freely circulates within a gap between the first and second capacitive plates thereby defining an oil deterioration sensor capacitor. The respective capacitances of the oil deterioration capacitor and the total reference capacitor provide an engine oil deterioration indication for the oil within the gap. The first capacitive plate is divided into a major sensing area, and a minor sensing area covering a relatively small portion of the total area of the first capacitive plate. The major sensing area and the second capacitive plate form the oil deterioration sensor capacitor.

Abstract: A sensor for determining both the presence of a liquid in a container or conduit, and identifying its type has a sensor housing body containing both a pair of piezoelectric elements used as the transmitter and receiver of ultrasonic waves directed across a gap therebetween in an ultrasonic liquid presence detecting circuit and a pair of electrodes exposed to any of such liquid in the gap used in a circuit for identifying the liquid type. The liquid identification circuit is either of the capacitance type, which produces a variable amplitude output signal depending on the type of liquid in the gap between the two electrodes, or operates to measure the difference in response time between pulses applied to each of the electrodes with one serving as a reference.

Abstract: A warning announcer for a gasoline dispenser having a pump flow counter, a pump bar switch and/or a nozzle position sensor, a dispenser nozzle, and a nozzle receptacle, including a logic unit, a timer, a speaker, a voice alarm unit for providing a message to the speaker, a circuit for connecting signals from the pump flow counter and the pump bar switch or position sensor to the logic unit for controlling the timer to produce a message signal, and a circuit for connecting the timer to the voice alarm unit for initiating a message when the timer produces a messages signals.

Abstract: A water faucet fitting seat capable of producing a musical tone or animal howl comprises a base and a sound producing device. The hollow base is provided therein with a channel having one end serving as a water outlet and another end which serves as a water inlet and can be fastened to the outlet of a water faucet. The base is further provided therein with a recessed seat having a round hole in communication with the channel. The sound producing device is disposed in the recessed seat and is provided with a speaker, a sound control circuit board and a conducting switch which is connected with the sound control circuit board and is provided with two terminals spaced at an interval and located in the channel via the round hole of the recessed seat.

Abstract: A method for selecting and implementing waveform processing techniques for a Bio-Sensor.RTM.. The ventilatory cycles of a fish are used to determine when an alarm state is present. Threshold techniques used in the waveform processing include a dynamic threshold method and a static threshold method.

Abstract: An air filter monitoring device for determining the condition of the filter in a forced air system having a two speed blower, wherein the device comprises a pair of air pressure sensing probes, one probe being downstream of the blower and filter, and the other probe positioned to detect ambient air pressure, an air pressure differential sensor which includes a first air pressure differential sensor member adapted to be actuated by a first differential pressure and a second air pressure differential sensor member adapted to be actuated by a second differential pressure, a control circuit selectively interconnected between the blower and the first or the second air pressure differential sensor members for interconnecting the first air pressure differential sensor member to the blower when it is operating at a first speed and for connecting the second air pressure differential sensor member to the blower when it is operating at a second speed, and a pair of clogged air filter indicating members which are respons

Abstract: A life indicator is so designed that an electric current flows to a light emitting diode utilizing a battery as a power source when two electrodes are electrically connected. The two electrodes are so installed as to be electrically connected by passing water through a water passage communicating with an objective equipment, and the discharge life of the battery is set equal to the service life of the equipment.

Abstract: A non-invasive, fluid monitor engages an open resonator with a segment of fluid line. The fluid line is disposed such that it and the fluid within become a part of the dielectric loading on the resonator. The open resonator is a part of an oscillator circuit that changes frequency of oscillation in response to the dielectric loading on the resonator. A frequency discriminator monitors the frequency of the oscillator to detect an air bubble in the fluid line. In the case where the resonator comprises a microstrip line, the microstrip line is disposed in parallel to the segment of the fluid line and the length of the microstrip line is selected to be equal to or greater than the maximum length of air bubble permitted thus providing a volumetric air-in-line sensor. The output of the frequency discriminator is compared to a threshold to determine a frequency shift large enough to indicate the presence of an air bubble.

Abstract: A monitoring system comprising at least, a first and a second indicator unit each associated with at least one fluid distribution line and each including at least two series of indicators, each series being associated with at least one pick-up of the magnitude of a fluid which circulates in a distribution line and comprising at least two indicator lights for the thresholds of the magnitude, wherein the thresholds may be adjusted by a programming unit.

Abstract: A fail safe output stage for a tank fluid level detection circuit having power supply/output leads periodically places a shunt across the leads to periodically generate a LOW signal which alternates with a HIGH signal to indicate an underfilled condition. In a filled condition, a steady signal appears across the leads. The output stage of the detection circuit consists of a parallel connection of switching devices where the "on" impedance of any single switching device is insufficient to place the detection circuit output lead in a LOW logic state. Therefore, in a condition where one of the switching devices fails, the detection circuit output may continue to alternate, but the alternating output is not recognized as such by a disable circuit which does not detect a LOW logic condition on the output lead. Accordingly, the failed output is interpreted as an filled condition, resulting in a shutdown of the system.

Abstract: An improved water quality monitor is provided for use in a water purification system of the type having a reverse osmosis unit for producing relatively pure water from a tap water supply. The reverse osmosis unit supplies produced purified water to a reservoir for storage until dispensing, as by opening a faucet valve. An inlet shut-off valve closes to prevent tap water inflow to the reverse osmosis unit when the reservoir reaches a substantially filled condition. The water quality monitor includes electrodes in contact with the tap water and the produced purified water to obtain comparative conductivity readings which represent the performance level of the reverse osmosis unit in removing impurities from the tap water inflow.

Abstract: An audio-visual alarm apparatus is provided for use with a water quality monitor having a pair of monitor nodes across which electrical conditions are indicative of whether the measured water quality is inside or outside of an acceptable quality range. The apparatus includes an audio-visual alarm and a circuit for energizing the alarm when the electrical condition across the monitor nodes is indicative of a measured water quality falling outside the acceptable range. The circuit includes a first relay for maintaining the circuit in a normally open position, and for closing the circuit when the relay is connected to the monitor nodes and a voltage condition across the monitor nodes is indicative of a measured water quality outside the acceptable range. Further, for certain monitors, it is possible to bypass the first relay by connecting the circuit directly to the monitor nodes.

Abstract: Concentrations of stock hydrogen peroxide-peracetic acid solutions can be monitored resistively. The resistivity cell electrodes have titanium surfaces which resist corrosion better than other electrode materials including platinum electrodes. Such resistivity monitoring is particularly useful to verify the concentrations of sterilant stock solutions used in machinery for cleaning and sterilizing medical and dental equipment such as dialyzer reuse machines. Over the temperature range of interest the resistivity measurement is substantially not affected by changes of temperature in the room temperature range.

Abstract: Apparatus and methods for determining that a piece of equipment, for example, used in the biotechnology or pharmaceutical industries, is clean are disclosed. The invention involves measuring the electrical conductivity of an aqueous liquid medium both before and after the medium is used to contact, e.g., rinse, the piece of equipment. The equipment is determined to be clean when these two measured electrical conductivities are substantially equal.

Abstract: A hydrocarbon leak detection system has a microprocessor based controller for receiving inputs from transducers and comparing the inputs against stored decision criteria to determine if hydrocarbons are leaking. The controller can receive and distinguish inputs from line pressure probes used for a product line tightness test, compare the line pressure probe inputs against stored decision criteria to determine status, and report the status.

Abstract: A sensor (1) is provided for sensing the entrainment of a fluid of low specific gravity in a fluid of higher specific gravity, particularly the entrainment of refrigerant gas in refrigerant liquid. The sensor (1) is typically installed into a higher pressure liquid supply line (24) of a refrigeration system (26). The sensor (1) has a differential float (16) including a float member (54) pivoted about a pivot (56) in a chamber (14) coupled to the supply line (24). The float member (54) has a specific gravity greater than the specific gravity of both of the fluids in which it operates. However, the location of the pivot (56) intermediate of the length of the float member (54) gives a net specific gravity for the differential float (16) which is less than the specific gravity of one of the fluids.

Abstract: A fail-safe system for the detection of water leaks, and for the prevention of damage therefrom. In a home or building which includes a hot-water tank and a water tank for a toilet, e.g., the damage-prevention system comprises valves for shutting off the supply of water to the tanks, and other valves for draining the tanks through discharge lines to the outside of the home or building. At the same time, power to the hot-water tank is shut off. A fail-safe water detector comprises a float with a metal cap, a first pair of electrical probes below the float, and a second pair of electrical probes above the metal cap and separated from the cap by an air gap. A circuit is closed in any of three ways: (1) when water contacts the first pair of probes, (2) when water raises the float and makes contact between the metal cap and the second pair of probes, and (3) when water contacts the second pair of probes.

Abstract: A sensor for detecting the presence of hydrocarbons and hydrocarbon containing fluids. It is formed of a first conductor which is formed of a metal wire or metal foil covered by an insulative sheath; a second conductor which consists of a hydrocarbon swellable elastomer and one or more conductive fillers; optionally an abuse/abrasion resistant jacket overlaying and preferably surrounding the two conductors and optionally a hydrocarbon permeable overcoat overlaying the jacket. The sensor may be in the form of a continuous length wire or a tape or a sheet. It may be coupled to an electric supply at one portion and a resistance indicator at the return portion. The resistance indicator is then attached to a signaling device such as a light or alarm.

Abstract: An apparatus for monitoring the condition of a pressure relief safety valve, which has a magnetic ball shiftable from a home position by fluid under pressure when the relief valve opens, and an adjacent sensor responsive to shifting of the ball to provide a signal representing an open valve.

Abstract: A sensor for monitoring the water content and the acid content in the presence of water in nonaqueous media can be incorporated into a monitoring system for monitoring the quality of nonaqueous fluids in equipment or vehicles. The sensor comprises an insulating substrate; electrodes formed on the substrate in an interdigitated pattern; and a conductive polymer deposited over the interdigitated electrodes which bridges between adjacent digits of the electrodes. The monitoring system incorporating the sensor comprises a control module for measuring the conductivity of the sensor. The control module is preprogrammed to compare the measured conductivity to a predetermined level indicative of an unacceptable level of degradation. The sensor is made by depositing electrodes on an insulating substrate; depositing a conductive polymer over the electrodes in an amount sufficient to bridge between the electrodes; and neutralizing the conductive polymer to an insulating form.

Abstract: A self-contained electronic monitoring unit for attachment to a device, such as a water filter, designed to be used until the occurrence of a predetermined event such as a predetermined number of uses, includes transducer for providing distinct outputs such as different audio output signals. A programmed integrated circuit and use detecting means such as electrical contacts detect each use of the device and monitor when the device is operational, when the end of life event is imminent and has occurred. The integrated circuit is programmed to operate the transducer to produce output signals during each use of the device informing the user that the device is operational, that the predetermined event or end of useful life is imminent and that the useful life has expired. The unit includes a battery for supplying power to the transducer and integrated circuit.

Abstract: In a fluidic flowmeter for measuring the flowrate higher than the preset flowrate by use of a fluidic element and for measuring the flowrate lower than the present flowrate by use of a flow sensor inserted into the nozzle portion, the present invention relates to the fluidic flowmeter that has an abnormality judging circuit for judging an abnormality and issuing a warning signal and also zero point and gain correcting circuits when operating the flowrate on the basis for the signal being output from the flow sensor in the case that the flowrate signal higher than the preset flowrate is to be input only from the flow sensor side and in the case that the flowrate signal higher than the preset flowrate is to be input only from the flow sensor side and in the event that the flowrate signal lower than the preset flowrate is to be input only from the fluidic element side.

Abstract: Two embodiments of a molten metal gauging and control system using a fixed position capacitance sensor and methods therefor are disclosed. The first embodiment discloses a molten metal gauging system, the output of which can be used by various different external control systems to adjust the flow of molten metal appropriately. The second embodiment discloses a molten metal gauging and control system that comprises the molten metal gauging system of the first embodiment in conjunction with a tapered pin positioner system as the element to control the flow of molten metal.

Abstract: A device is provided which passes light of preselected wavelengths through a fluid or vapor to be tested. The light is detected after it has passed through the fluid or vapor. Upon detection, a voltage is created which is proportional in amplitude to the detected light strength for each wavelength of light. These voltages are compared to produce a ratio which represents the condition of the fluid or vapor which is tested. When the ratio is outside of preselected boundaries, control signals are generated which may trigger alarms or otherwise respond to the condition.

Abstract: An apparatus controls the treatment of water that flows through a cooling system. The electrical conductivity of the water is sensed. A valve control opens a system drain valve when the sensed conductivity is greater than a threshold, and closes the drain valve when the conductivity drops below the threshold by a given amount. The water drained form the system is replenished through an inlet and a mechanism measures the volume of water added to the cooling system. Chemicals to treat the water are fed into the system when specified volumes of water have been added. The sensing of conductivity can be inhibited for a certain period following the application of the chemicals. A possible system malfunction is indicated when the conductivity does not drop below the threshold after the drain valve is open for a given period of time.

Abstract: A pressure monitoring device for indicating to the administrator of an injection to a patient that an excess of force has been exerted on the plunger and thereby the fluids contained within the syringe.

Abstract: The invention concerns a simple, inexpensive and small detector, particularly for use in the medical pumps, for detecting over-pressure in a pipe (1) and setting off an alarm when an over-pressure is detected. The detector for detecting over-pressure in the pipe (1) along which a fluid (3) flows may comprise a T junction (5) for deriving a fraction of the flowing fluid (3) from the pipe (1); at least one tube (7) wherein there is fitted at least one obturating member (9); and an assembly for detecting the displacement of the obturating member (9) in the tube (7) and for generating a signal in response to detecting displacement of the obturating member (9).

Abstract: A fail-safe system for the detection of water leaks, and for the prevention of damage therefrom. In a home or building which includes a hot-water tank and a water tank for a toilet, e.g., the damage-prevention system comprises valves for shutting off the supply of water to the tanks, and other valves for draining the tanks through discharge lines to the outside of the home or building. At the same time, power to the hot-water tank is shut off. A fail-safe water detector comprises a float with a metal cap, a first pair of electrical probes below the float, and a second pair of electrical probes above the metal cap and separated from the cap by an air gap. A circuit is closed in any of three ways: (1) when water contacts the first pair of probes, (2) when water raises the float and makes contact between the metal cap and the second pair of probes, and (3) when water contacts the second pair of probes.

Abstract: A protective composite liner for installation inside a vessel, such as a supertanker, is proposed with an outer layer of high strength fibers, a middle layer of flexible, high strength, resilient film material, and an inner chemical resistant layer. Means for anchoring the protective composite liner and sensor means for detecting a leak are further provided for use with the liner of the present invention.

Abstract: An automatic leak detection apparatus for process fluids from production and/or research plants, in particular energy plants comprises three different and separate sets of sensors, the first of which analyzes signals sensed in the visual spectrum through a telecamera, the second set analyzes signals sensed in the infrared spectrum through a thermocamera, and the third set analyzes qualitatively and quantitatively any change in the composition of the environmental atmosphere through a chemical-excitation mass spectrometer, and means adapted to process data supplied by said three sets of sensors, to compare said data with reference data, to store said data, to generate alarm signals at different levels, and to give assistance, if necessary.

Abstract: A non-intrusive liquid flow detection apparatus for detecting liquid flow in a select pipe, the flow generating a sound wave of known frequency and wavelength. The apparatus includes a pair of transducers spaced along the select pipe approximately one-half wavelength apart. In-phase transducer signals are generated for liquid flow through the select pipe, while out of phase transducer signals are generated for flow from remote pipes. Respective band-pass amplifiers receive and amplify the transducer signals passing the portion within a narrow-band corresponding to the known frequency of the flow sound waves. The amplified signals are summed to cancel out of phase signal components attributable to flow through remote pipes. Thus, high amplitude signals are generated only by fluid flow through the select pipe. The real time summed signal is compared to a time-averaged background noise signal to avoid inadvertent triggering from non-fluid flow sounds of similar sound print.

Abstract: The invention provides a sensor whose conductive sheet is composed of substantially non-cross-linked thermoplastic elastomer and conductive carbon. The conductive sheet has a maximum of 70 of Shore A-hardness. By virtue of the above structure, the sensor very sharply responds to electric resistance of the conductive sheet against presence of low molecular weight organic liquid such as gasoline and vapor thereof to quickly detect leaked organic liquid or vapor with extremely sharp sensitivity. Furthermore, the detection system of the invention using the above sensor has a simple circuit which precisely detects varied electric resistance of the conductive sheet. The detection system characteristically incorporates an alarm generator to instantly warn operators of the presence of leaked organic liquid such as gasoline and vapor thereof.

Abstract: A liquid presence detector and method of using the same for a gas fluid pipe includes a helically wound insulated wire positioned inside the pipe such that an outer periphery of the wire contacts an inner surface of the pipe along an axial portion thereof. The pipe and wire form two plates of a capacitor with the pipe being connected to electrical ground for electromagnetic shielding and shock protection. The wire plate of the capacitor contacts liquid particles that travel along the pipe wall. A circuit is provided to measure capacitance between the wire and the pipe to detect liquid contacting the wire and pipe.

Abstract: A system for determining the magnitude of loads on rotating helicopter components from sensor signals remotely measured on the helicopter fuselage is characterized by a controller which samples the sensor signals according to phase. These measured signals are presented to a coefficient programming module where they are combined with correlation signals to correlate the measured signal components with the desired parameter, such as flatwise bending moments of a helicopter blade. The correlation signals are established in a calibration process that determines the independent values of the measured signals using a Jones orthoganization process. The signals output from the module are recombined to provide a time dependent signal corresponding to the desired parameter. The present system avoids decomposition and recomposition of the measured signals and therefor operates in real time.

Abstract: A water quality monitor is provided for use in a purified water supply system of the type having a reverse osmosis unit for producing relatively purified water from an ordinary tap water supply. The monitor includes a control circuit having electrodes in contact with the purified and tap water supplies. The control circuit is activated by depression of a test button, preferably in response to opening of a faucet valve to dispense water, to produce a short duration pulse of one polarity which is connected to the electrodes for use in determining the water conductivities. The control circuit compares the conductivities of the purified and tap water supplies, and maintains an appropriate indicator light in an illuminated state until the test button is released, at which time the control circuit couples a short duration pulse of opposite polarity to the electrodes for minimizing electrode corrosion and/or accumulation of ionic deposits.

Abstract: A carrying safety device for a medical dropper, having a housing, a lifting/lowering controller, a dropper bottle and an auto-controlling system, wherein the housing has several chambers and provided with two ring buckles, in connection with a carrying belt for placing on the patient's back; the lifting/lowering controller is located in the housing with an extending/retracting portion extending outside the housing; the dropper bottle is connected with and controlled by the extending/retracting portion to be raised above the patient's chest or lowered into the housing; the auto-controlling system is disposed with operating switches and an encoder on an operating panel mounted on the housing or on the carrying belt, and includes a lifting/lowering drive circuit, a signal transmitter and receiver; the signal transmitter has an encoder set-up with a transmitter code and a mercury balance switch whereby an emergency rescue signal may be transmitted; a manual switch is provided for the patient to activate the rescu

Abstract: An oscillator for use in a fluid detection apparatus for determining the respective percentages of first and second liquids in a mixture disposed within a chamber, including an inductive element immersed in the mixture such that the mixture at least partially determines a value of distributed capacitance exhibited by the element when energized; where the inductive element is a coil acting as a resonant element in an oscillator, and where the oscillator is of the tuned input type such that the coil and its distributed capacitance define a parallel resonant tank circuit which generates an oscillating signal at a resonant frequency of the tank circuit, the resonant frequency being inversely proportional related to the distributed capacitance of the coil.

Abstract: This invention is directed to a boiling detecting device for a stove. In particular, the boiling detecting device is directed to one utilizing vibration produced by the boiling water to trigger an electronic circuit to turn off the gas supply, or the stove's power supply, or the like. The device comprises a vibration detecting support, a vibration sensor, a frequency to voltage converter, a voltage detector, a driving stage, and safety device.

Abstract: A fluid status detection system includes a plurality of probes connected to a controller. The controller includes a number of relays that may be programmed to latch either open or closed upon receipt of any one of several different alarms from the probes. The system includes a function that if a relay is latched and a second alarm occurs, then the relay releases for a second, then relatches. The system permits an operator to select the release and relatch latch function individually for each of the relays and to store the selection in a digital memory.

Abstract: A water quality monitor is provided for use in a purified water supply system of the type having a reverse osmosis unit or the like for producing relatively purified water from an ordinary tap or feed water supply. The monitor includes a control circuit having eletrodes in contact with the purified and tap water supplies. The control circuit is activated by depression of a test button to produce a short duration pulse of one polarity which is connected to the electrodes for use in determining the water conductivities. The control circuit compares the conductivities of the purified and tap water supplies, wherein this comparison represents the operational efficiency of the purification system in removing contaminants from the incoming tap water. The control circuit responds to this comparison to illuminate an appropriate indicator light or the like and thereby indicate the operational state of the purification system.

Abstract: A medical gas alarm system is provided which includes a sensor unit pneumatically connected to a medical gas supply line and a switch connected to a valve in the supply line for detecting the open condition of the valve. In the event either the sensor detects a high pressure or low pressure condition in the supply line or the switch is activated by closing of the valve, an alarm signal is received by an alarm module and an alarm is activated. The alarm may be visual, audible or both. During normal operations, the alarm module displays both a system on condition and a digital display indicating the pressure in the supply line.

Abstract: An apparatus and method for determining the position of an object, especially the position of a movable object in an industrial vessel. The position is determined by the use of two signals having a very large difference in their velocities, such as electromagnetic and acoustic waves. The object whose position is to be determined receives the electromagnetic signal, analyzes the electromagnetic signal, and, if appropriate, transmits an acoustic signal. In addition to the object containing an electromagnetic receiver and an acoustic transmitter, there is required an electromagnetic transmitter, three or more receivers to receive the acoustic signal from the object, and supporting equipment to process signals and log data. When the object transmits an acoustic signal, the acoustic receivers, which are in known positions in the vessel, receive the signal at different times depending on the distance of the object from each receiver.