Abstract: The detector for detecting the presence of a liquid comprises: a) a metal veguide having a solid cylindrical top first portion of relatively small section with an outside diameter having a first value d1, which first portion is fixed on a support, a cylindrical rigid bottom second portion whose outside diameter has a second value d2 greater than the first value d1, which second portion extends the first portion downwards and is connected thereto by a short linking portion; b) transducer means disposed in the vicinity of the top portion of the waveguide; and c) electronic processing means. The value of the frequency at which the transducer means are excited is selected in such a manner that acoustic wave trains propagate in the cylindrical first portion at the group velocity of low frequency waves, and propagate in the cylindrical second portion at the minimum group velocity corresponding to the point of inflection in the curve of phase velocity as a function of frequency.

Abstract: A coin tube monitor and control device for monitoring and controlling the number of coins in a coin tube by determining the time between when a coin enters a coin tube and when it strikes the stack of coins that has accumulated therein. The device includes an acoustic sensor for responding to certain movements of the coins.

Abstract: Method for determining the volume of fluid produced and other production characteristics from a subterranean formation during a drill stem test based on determining the location of well fluid within the drill stem tubing by measuring the travel time of an acoustic signal reflected from the well fluid.

Abstract: An ultrasonic liquid level detector mounted in a fill pipe cap. The ultrasonic detector mounted in a fill pipe cap (10) is used in determining a level and/or the volume of a liquid (5) stored in an underground storage tank (20). The fill pipe cap contains an ultrasonic ranging unit (50) that measures a time, T.sub.L, required for an ultrasonic pulse to travel round trip between an ultrasonic transducer/receiver (54) and the surface of the liquid in the tank. A reference reflector (25) disposed within a fill pipe (30) is used in determining a reference time, T.sub.R, that is included in a non-linear expression, e.sup..alpha. .multidot.T.sub.L.sup..beta..sbsp.1 .multidot.T.sub.R.sup..beta..sbsp.2, in order to compute the level of liquid in the storage tank. The terms e.sup..alpha., .beta..sub.1, and .beta..sub.2 comprise a correction for errors in the round-trip times T.sub.L and T.sub.R caused by a non-uniform vapor density of the liquid along the path traveled by the ultrasonic pulses.

Abstract: A magnetostrictive transducer measuring system for precisely measuring the liquid level of fuel in an underground tank. The system provides for the measurement of the position of one or more transducer magnets in a tube that are positioned along a length of the transducer wire therein, with one of the magnets fixed in the tube to provide a reference position. A current pulse is applied to the transducer wire and sonic pulses are simultaneously produced through the interaction of the magnetic field of the transducer wire and the fields of the magnets. The sonic pulses are detected by a sensor and the time interval between the detected sonic pulses is determined to determine the distance between the magnets.

Abstract: A system for sensing the level of contents in a container is disclosed. A tubular member is vertically disposed in the container and sealed from the contents of the container. A marker located in the tubular member and generating a peripheral polarized magnetic field, is levitated at the height of float means located around the tubular member buoyed on the contents of the container and generating a polarized magnetic field within the tubular member of like polarity beneath the polarized magnetic field of the marker. A depth transducer located at one end of the tubular member forms part of a pulse-echo ranging system which calculates ranges on the basis of a time lag between emission of an ultrasonic signal by the depth transducer and receipt of at least one return echo signal from the marker in order to determine the depth of the marker in the tubular member, and indirectly, the level of contents in the container.

Abstract: A device for gauging the level of a fluid in a container having a gas above the surface of the fluid. The device comprises a microwave transmitter transmitting a microwave radio signal through the gas to the surface and a receiver for receiving the microwave signal reflected by the surface. An electronic unit is arranged to calculate from the propagation time of the microwave signal a first distance from the transmitter to the surface of the fluid and thereby the level in the container. The microwave signal is preferably within the radar frequency range. A sound transmitter is also provided for transmitting a sound signal through the gas to the surface of the fluid and is capable of receiving a sound signal reflected from the surface of the fluid. A means is provided for correcting the first distance to a second corrected distance as a function of the microwave velocity and the known relation between the sound velocity and the microwave velocity.

Abstract: An accurate measurement of liquid levels in a tank are made using a dual tube sonic level gage. This uses plane waves of sound, in air, propagated in two vertical tubular wave guides to locate the levels of liquid contained in each tube. One tube has slots at the bottom and allows both the light (upper) and the heavy (lower) liquids to be present inside the tube at the same level as outside (i.e. in the tank). The other tube allows only the lower liquid to enter it. In the application for a measurement of gasoline and water levels in a tank, levels outside the tube (i.e. in the tank) are calculated using the equations of hydrostatics. Corrections due to temperature need not be made in order to obtain levels accurate to 1 percent.

Abstract: An ultrasonic bin level control circuit which employs a fail-safe circuit to shut off a compressor when echoes are late or absent, and a transducer mounting system which facilitates installation and removal of a transducer for servicing and cleaning. A level detector compares a reference signal with a reflected signal, the ice reaching a desired level when the reflected signal overlaps the reference signal. When the desired level is reached, the reference signal is modified through feedback to prevent short cycling of the compressor. The transducer is installed within a cylindrical housing which is easily installed and removed from a cylindrical socket within a compartment above the bin.

Abstract: An automatic, ultrasonic system for controlling the filling of different sizes of beverage containers which may or may not contain various quantities of ice. The system includes a transducer assembly and a control module, both preferably connected to a beverage dispenser valve assembly. The transducer assembly includes at least two piezo-electric crystals for separately transmitting and receiving ultrasonic wave energy from the grate, the cup lip, the top of any ice in the cup, and the rising liquid level, and for generating signals corresponding to the travel time of the ultrasonic energy. The control module includes a microcomputer and associated circuitry. The system can include two separate transmitter and receiver crystals, or in a preferred embodiment two transmitter-receiver paris of crystals.

Abstract: The invention relates to a method and an apparatus for investigating a filling of liquid in a container, e.g. a fuel tank in respect of actual volume, density, temperature, opacity or other condition. From an emitter (19) at the bottom of the container there are emitted pulses of ultrasonic waves which are reflected by one or more horizontal border faces (17, 21) of the liquid and returned to the bottom of the container and detected by a receiver (20) there. The passage times of the reflected signals are compared with the passage times of direct and not-reflected signals that are detected by a plurality of receivers (1, 2, 3, 4, 5) placed above each other in fixed known positions. The result of said comparison is made the basis of a calculation of the sought quality. Measurement of the passage times, comparison, calculation and exposition of the result takes place by the use of electronic or data equipment (23).

Abstract: The ultrasound detector for a thin film includes an ultrasound transmitter and an ultrasound receiver. It is generally known that a plastic film introduced into a sound field attenuates the field to a greater or lesser degree. A sound wave of a frequency of e.g. 40 kHz has a wave length of approximately 9 mm in air. When a plastic film of a thickness of, e.g., 0.50-0.10 mm is introduced, the sound field is typically attenuated with 6-20 dB. The the ultrasound detector is formed as a resonator, and the distance between the transmitter and the receiver corresponds substantially to an integral multiple of one half of a wave length. As a result, the obtained sound field is stronger than previously and the attenuation caused by a plastic film between the transmitter and the receiver is higher than previously. Furthermore, the ultrasound frequency is scanned for taking tolerances, such as changes in temperature and humidity of air into account.

Abstract: A fluid level monitor for monitoring the fluid level in a tank comprises a first pair of transducers arranged in a vertically upper horizontal plane and a second pair of transducers arranged in a vertically lower horizontal plane. Pulse generators send electrical pulses to the transmitter transducers which transmit stress waves into the wall of the tank. The stress waves propagating peripherally are detected by the receiver transducers and processors analyze the amplitude of the detected stress waves to determine if the fluid is present or absent at the upper and lower horizontal planes. The pulse generators are arranged to send pulses out of phase so that stress waves propagating axially can be detected to determine alterations of the fluid level between the upper and lower horizontal planes. The processors may be arranged to operate alarms or to operate valves to control the fluid level in the tank.

Abstract: Acoustical energy is directed into a vessel containing an unknown volume of fluid at a frequency at or near the Helmholtz resonance of the vessel. The signal generated within the vessel is analyzed to compare its phase relationship to an electrical reference input signal. The volume of fluid in the vessel may then be determined from said phase relationship, such as by previous empirical calibration of the vessel.

Abstract: In acoustic level sensing apparatus, in which pulses of acoustic energy are transmitted by an electrically energized transducer towards a surface to be sensed, and the electrical output from the transducer following the pulse is digitized and analyzed to detect a return echo from the surface, so as to produce a digitized echo profile. The digitzed echo profile is enhanced by removing narrow peaks likely to correspond with certain types of spurious echo, and narrow valleys which may represent fragmentation of a wanted echo. Echoes are identified by comparing the profile with a time varying threshold generated derived from a linear regression performed on part of the threshold, various different types of comparison being performed and their results combined prior to selecting the most likely true echo on the basis of the combined results.

Abstract: The filling level meter for measuring the filling level in a container includes a transmitting and a receiving arrangement which directs sonic or ultrasonic pulses onto the filling material surface and receives the backscattered pulses reflected by the filling material surface and converts them to electrical reception signals. Connected to the transmitting and receiving arrangement is an evaluating circuit which in a signal processing path generates an envelope signal corresponding to the envelope of the reception signals, digitizes sampled values of the envelope signal, stores in a memory the digitized sampled values for creating a distance-dependent or travel-time-dependent amplitude profile of the measurement distance and evaluates the amplitude profile for determining the travel time of the most probable useful echo signal.

Abstract: An ultrasonic sensor for fluid levels comprises a carrier having spaed-apart legs with registering openings adapted to receive a piezoelectric transmitter and a piezoelectric receiver in the openings. The piezoelectric members are separated by the spaced legs of a ground plane engaging plates of the piezoelectric members. Resilient members in the form of coiled conductors are entrained between a snap-on cover and the transducers so as to resiliently engage the piezoelectric members against the ground plane. The conductors are coupled by crimp connectors to the leads of a cable carried by an elongated channel portion of the carrier. The crimp conenctors are caried in recessed portions of the carrier, and the carrier is over-molded to encase the connectors and the cable. The cable is in turn coupled to an electronic control module positioned remotely from the fluid sump and connected to a warning device.

Abstract: An automatic ultrasonic system for controlling the filling of different sizes of beverage containers which may or may not contain various quantities of ice. The system includes a transducer assembly and a control module, both preferably connected to a beverage dispenser valve assembly. The transducer assembly includes at least two piezo-electric crystals for separately transmitting and receiving ultrasonic wave energy from the grate, the cup lip, the top of any ice in the cup, and the rising liquid level, and for generating signals corresponding to the travel time of the ultrasonic energy. The control module includes a microcomputer and associated circuitry. The system can include two separate transmitter and receiver crystals, or in a preferred embodiment two transmitter-receiver pairs of crystals.

Abstract: A rod shaped or tubular housing for a sensor includes an interior space provided with upper and lower compensating openings and within which an ultrasound measured distance device. Below the ultrasound measured distance device, the interior is connected to the lower compensating opening through a narrow channel proceeding in an axial direction of the housing. The housing is formed of two half shells of plastic joined to one another whose wall parts engage into one another to form the narrow channel. The ultrasound transducers and the electrical leads are embedded into the half shells. A second ultrasound measured distance device which is in direct communication with the surrounding space may be provided above the interior space. The ultrasound transducer of the measured distance device is excited to transmit in a pulsed fashion.

Abstract: The sensor device for detecting the presence or absence of a liquid (2) at predetermined level (N) in a tank (1) comprises a transmitter transducer (51; 51'; 61), a receiver transducer (52, 52', 62), and electronic means (100) for processing the signals applied to the transmission transducer and delivered by the receiver transducer. In the vicinity of the predetermined level (N) of the tank (1), the device includes a detection plate (50; 50', 60) having at least one face (58) which comes into contact with the liquid (2) when the liquid reaches that level. The detection plate carries the transmitter transducer which is disposed for locally generating Lamb waves in the plate, and the plate also carries the receiver transducer which is disposed for detecting the presence or the absence of Lamb waves transmitted along the plate.

Abstract: A monitor for detecting the presence of liquid in a fluid supply conduit wherein the fluid has at least a liquid phase, and wherein bubbles may form in the fluid, is shown to include an ultrasonic signal transmitter for generating and transmitting an ultrasonic signal, an ultrasonic signal receiver, means for attaching the transmitter and receiver to the conduit, and a waveguide which confines a portion of the fluid so that the ultrasonic signal is guided to the receiver when liquid is present in the confined portion. The waveguide also tends to exclude bubbles from the confined portion. The waveguide may include a cylinder positioned in the conduit between the transmitter and the receiver and which has a plurality of openings to allow the ingress and egress of liquid.

Abstract: An automatic, ultrasonic system for controlling the filling of different sizes of beverage container which may or may not contain various quantities of ice. The system includes a housing, a front and a rear pair of separate transmitter and receiver crystals mounted in the housing with a lens on the lower surface of each crystal. Each crystal is located within a separate non-ferrous metal tube. Polyurethane foam fills the space within the housing and the tubes.

Abstract: An automatic, ultrasonic system for controlling the filling of different sizes of beverage containers which may or may not contain various quantities of ice. The system includes a transducer assembly and a control module, both preferably connected to a beverage dispenser valve assembly. The transducer assembly includes at least two piezo-electric crystals for separately transmitting and receiving ultrasonic wave energy from the grate, the cup lip, the top of any ice in the cup, and the rising liquid level, and for generating signals corresponding to the travel time of the ultrasonic energy. The control module includes a microcomputer and associated circuitry. The system can include two separate transmitter and receiver crystals, or in a preferred embodiment two transmitter-receiver pairs of crystals.

Abstract: An apparatus (10) is disclosed for permitting continuous calculations of the depth of the fluid level (12) within a well bore (14) during a test interval. A sonic event is generated in the well bore, and the reflected sonic signals from down hole tubing collars and the fluid surface are sensed and recorded. By knowing the depth of the tubing collars, the fluid depth and speed of sound in the oerlying gas can be computed. Subsequently, the apparatus (10) generates sonic events and records the travel time for the sound to reflect off the fluid surface and return. Measurements of the actual fluid depth and sonic velocity are made at regular intervals, and interpolated between actual measurements to allow the variation in fluid level to be calculated from the measurements of travel time.

Abstract: In a method of indicating the time of an acoustic pulse at the transmission or reception of the same, the acoustic pulse is a wave package, the amplitude envelope of which having an ascending and a descending flank. The method is characterized in that the beginning of the descending flank of the amplitude is detected for determining of a reference time in the wave package, that a predetermined zero crossing in the wave package is identified from the reference time and that the time of the identified zero crossing is determined.

Abstract: A system for measuring the level of a fluid in a tank comprises a plurality of reflectors positioned in the tank with the reflectors being a known distance from one another and a first reflector being an unknown distance from the top of the tank and an apparatus for producing and outputting a sonic signal and for receiving echoes from the plurality of reflectors and a surface of the fluid in the tank. The apparatus produces electrical signals representative of the received echoes. The apparatus includes a processor responsive to the electrical signals for, (i) calculating the distance between the apparatus and the first reflector, (ii) calculating the distance between a last reflector and the fluid surface, and (iii) determining the total distance from the apparatus to the fluid surface based on the distances calculated in (i), (ii), and the distance between the first and last reflectors.

Abstract: The invention relates to apparatus for measuring storage parameters such as level and temperature relating to immiscible liquids or fluids in a tank. The apparatus comprises a pulse generator (1) for generating pulses which are applied to a delay line (3) with reflected pulses being representative of the depths of the various liquids constituting propagation transitions through different media (I, II, III, IV, etc.). Logic means (Li) are switched on by a measurement pulse (Im) and they are switched off by corresponding reflected pulses (Ii) generated by transitions of order i. Integrator means (Ji) for integrating the signals delivered by the logic means (Li) serve to generate respective voltages proportional to the time lapse between the measurement pulse (Im) and each of the reflected pulses (Ii) under consideration. Multiplexer means serve to sequentially deliver the measured values corresponding to the different liquids of order i in the tank.

Abstract: A tank level meter includes an elongated sound conductor of a solid material extending over the entire height of the tank. A sound generator is coupled to one end of the sound conductor to excite thereon surface waves and the opposite end of the conductor is coupled to a sound receiver. Due to different acoustic impedances of the material of the sound conductor of the fluids present in the tank that means of the air and of the liquid whose level is to be measured, the sound waves propagating at the interface of the sound conducting member and fluids arrive to the receiver with a phase shift which is proportional to the liquid level in the tank. By a suitable selection of materials of the sound conductor it is possible to obtain an unambiguous measuring signal at the receiver or a measuring signal having a high resolution. By using at least two sound conductors in the tank it is possible to obtain both a single value volume reading and a high resolution.

Abstract: An ultrasound liquid level detector system for automatically controlling the dispensing of a post-mix beverage, including microprocessor-controlled circuitry for monitoring and implementing the automatic dispensing process. The microprocessor is interfaced with an ultrasonic transducer which transmits ultrasonic wave energy towards the container to be filled and receives reflected ultrasonic wave energy, the characteristics of which are analyzed within the microprocessor to implement control functions of the automatic dispensing process. Dispensing automatically begins as a container is inserted under the ultrasonic transducer into a proper position beneath a post-mix beverage dispenser nozzle. The transducer continuously measures the distance between the top or lip of the container and a liquid/foam interface of a carbonated beverage being dispensed into the container. Dispensing stops when the transducer senses a predetermined level of carbonated beverage within the container.

Abstract: An ultrasonic level gauge that measures the level of a test surface inside a tank. A guiding pipe guides the ultrasonic wave transmitted by an ultrasonic transceiver to the test surface, and guides the ultrasonic wave reflected by the test surface back to the ultrasonic transceiver. An extended portion that extends the propagation distance of the ultrasonic wave guided by the guiding pipe may be provided on the basal portion of the guiding pipe. In this case, the ultrasonic transceiver is provided at the opening at the end of the extended portion. Also, a helical portion or a slanting portion may be provided in the guiding pipe to make the ultrasonic wave transmitted by the ultrasonic transceiver enter the test surface in a slanting direction.

Abstract: A non-intrusive acoustic sensor system for detecting and displaying the location of the level of a liquid in a tank uses a piezoelectric transceiver mounted to a bottom exterior location on the tank. The transceiver is an element of a driving and signal processing circuit which also includes a readout device for displaying liquid level location in selected terms. The system circuitry includes a microprocessor programmed to enable the velocity of sound in a liquid in the tank to be determined by the system at the site of use from a single distance measurement descriptive of the usage situation. The system automatically selects and uses the transceiver acoustic emission frequency which is best for the tank and liquid combination of interest at any time. The system, in a dual-transceiver configuration described, determines and uses speed of sound in the liquid as it in fact exists at any time.

Abstract: An apparatus for activating and deactivating a bilge pump in a marine vessel in response to the presence or absence of water or other fluid in the bilge area wherein a pair of acoustic transducers are mounted in proximate and opposed relationship to one another such that a first transducer, the generator transducer, transmits acoustic waves to a second transducer, the receiver transducer, across a designated narrow channel. The apparatus operates on the principle that acoustic waves transmit greater energy in a dense transmission medium such as water or other liquid. The sensitivity of the transducer pair and its associated electronic circuitry is adjusted such that the transmitted acoustic signal is detected at the receiver transducer when the signal is transmitted through liquid and the signal fails to reach a detectable level at the receiver transducer when the signal is transmitted through air. The detected signal triggers electronic circuitry operating a relay coil which switches power to the bilge pump.

Abstract: A tank level meter includes an elongated sound conductor of a solid material extending over the entire height of the tank and having a coating partially surrounding it. A sound generator is coupled to one end of the sound conductor to excite thereon surface waves and the opposite end of the conductor is coupled to a sound receiver. Due to different acoustic impedances of the material of the sound conductor of the fluids present in the tank that means of the air and of a liquid whose level is to be measured, the sound waves propagating at the interface of the sound conducting member and fluids arrive to the receiver with a phase shift which is proportional to the liquid level in the tank. By a suitable selection of materials of the sound conductor and coating it is possible to obtain an unambiguous measuring signal at the receiver or a measuring signal having a high resolution. By using at least two sound conductors in the tank it is possible to obtain both a single value volume reading and a high resolution.

Abstract: A method for automatically filling beverage containers from a pair of adjacent beverage dispensing valves including transmitting ultrasonic energy down from each valve and receiving reflected ultrasonic energy to detect a container, filling the detected container, and operating each valve separated in time by synchronizing their operation to different half cycles of an a.c. power supply, to prevent interference therebetween.

Abstract: In acoustic level sensing apparatus, in which pulses of acoustic energy are transmitted by an electrically energized transducer towards a surface to be sensed, and the electrical output from the transducer following the pulse is digitized and analyzed to detect a return echo from the surface, so as to produce a digitized echo profile. The digitized echo profile is enhanced by removing narrow peaks likely to correspond with certain types of spurious echo, and narrow valleys which may represent fragmentation of a wanted echo. Echoes are identified by comparing the profile with a time varying threshold generated derived from a linear regression performed on part of the threshold, various different types of comparison being performed and their results combined prior to selecting the most likely true echo on the basis of the combined results.

Abstract: An ultrasonic, echo-ranging instrument for measuring liquid level, the instrument including a transducer dispoed at a fixed position directly above the liquid surface. The transducer is excited to emit periodic pulses which are intercepted by the liquid surface as well as by a reference point a fixed distance from the transducer to produce both reference and liquid echo pulses that are returned to the transducer and detected thereby. The respective transit times of the reference echo and the liquid echo pulses are determined, and the ratio between these transit times is computed to provide an output representing the level of liquid. To ensure accurate readings, the reference echo and liquid echo pulses from the transducer are fed to a single automatic gain control circuit whose operation is time shared.

Abstract: In one embodiment of a technique for monitoring scouring around structural members which are at least partially submerged in the soil bed material at the bottom of a body of water, the distance between a fixed point on the structural member and the topmost portion of the soil bed material near the member is determined and compared to a predetermined value. When scouring occurs, removal of some of the soil bed material results in an increase in the measured distance, which increase can be used to indicate the occurrence of scouring in an appropriate manner, such as by utilizing a display, by recording the data, or even by telecommunicating the data to another location. The distance determination may be made either only when called for or periodically at predetermined times, in order to provide continuous monitoring. In an alternative embodiment, scour monitoring is provided by one or more probes disposed so as to initially rest on top of the soil bed material located near the structural member.

Abstract: Apparatus and method for obtaining from a well drilled into the subsurface of the earth the information necessary to determine the location of the liquid surface in same. A source of pressure pulses is coupled to the well surface casing in order that the pulses are transmitted downhole where they are reflected by all surfaces present therein such as, the liquid surface, tubing collars and tubing anchors. A transient pressure transducer is provided which generates an electrical output in response to all reflections of the transmitted pulse. All of the reflections occurring in the well are recorded for a sufficient amount of time to ensure the recording of the first reflection from the liquid surface present in the well.

Abstract: Apparatus (1) for measuring the amount of a substance (2) in a vessel which comprises a detector means comprising at least two electrodes (3) adopted to generate an electric signal in response to contact of the electrodes with the surface of the substance (2), a first reference point (6) on the detector means which point is a fixed distance from the ends of the electrodes (3) said reference point being provided on a material suitable for reflecting waves from a wave transmitting-receiving device (8) e.g. a sonar device, preferably located in a fixed position above the first reference point for measuring the distance from the first reference point (6) to a second reference point (70) at the wave transmitting-receiving device (8) whereby the amount of the substance (2) in the vessel can be determined by computation, e.g.

Abstract: In a detection device of the presence of frost and/or measuring the thickness of the frost by ultrasound, a probe with a piezoelectric ultrasonic transducer generates an ultra-sonic acoustic emission wave and detects ultrasonic acoustic echo waves reflected by the frost. An actuating device for the probe is arranged to provide to the transducer electrical energizing signals. The probe comprises: a frost detector placed in front of the transducer and constituted of a material having an acoustic impedance between 30.times.10.sup.5 and 44.times.10.sup.5 kg m.sup.-2 s.sup.-1. This detector has a surface designed to be exposed to the surrounding atmosphere to be covered with frost. An acoustic delay device is adapted to ensure acoustic coupling and adaptation between the transducer and the detector and to separate in time the ultrasonic emission add reflected waves. A body of heat insulating material covers the assembly of the detector, the transducer and the acoustic delay device.

Abstract: An improved microprocessor-controlled sonar depth sounder, which is automatically operative to detect and lock to the bottom of a body of water, fill in the display below the detected bottom, change display scales in response to the detected bottom going off-scale, and reformat the entire display in response to a scale change. A memory is provided for storing target data up to the operable depth limits of the device, thereby allowing display reversing and display expansion or "zoom" of a predetermined portion of the display selected by a zoom cursor. The zoom or cursor is variably positionable at different depths. The device employs an improved variable sensitivity amplifier. Also disclosed is an improved water-resistant switch construction for marine electronic equipment.

Abstract: An ultrasonic echo-ranging meter for measuring the changing level of liquid in a tank or open channel, the meter including a transducer at a raised position above the liquid surface. Pulses of ultrasonic energy transmitted by the transducer are directed toward the liquid surface and reflected thereby to produce main echo pulses that are picked up by the same transducer. The round trip transmit time of the pulse energy in the gaseous medium above the liquid depends on the distance between the transducer and the liquid surface, this time being measured to provide a reading of liquid level. Also intercepted by the transducer are parasitic echo pulses originating from reflecting wall surfaces and other obstacles in the vicinity of the tank or channel, which parasitic pulses may be confused with the main echo pulses and result in an erroneous reading.

Abstract: Programmable apparatus for monitoring an industrial installation, such as for measuring the depth of material in bins or silos, utilizes a computer having a hermetically sealed case, with an externally visible display and necessary connections to the installation being monitored. The computer includes non-volatile random access memory for the storage of operating parameters which is written to under control of a portable external programming unit which can temporarily access the computer via an infrared or equivalent communications link. The case of the computer has provision for temporary docking of the programming unit, which has a keypad for the selection of calibration and diagnostic routines, and the entry of data or commands to be transmitted to the computer.

Abstract: An apparatus measures changes in groundwater pressure in a borehole. The apparatus comprises: a probe consisting of a hollow tube having a smooth interior surface, an ultrasonic transmitter which emits ultrasonic waves down the interior of the tube, and an ultrasonic receiver which receives and registers the reflected ultrasonic waves; a means to raise and lower the probe so the tube is partially submerged in the groundwater; a means to control the emission of ultrasonic waves; a means to convert the time interval into a distance or pressure measurement; and a means to store or transmit the data.

Abstract: Ultrasonic apparatus for measuring and remotely displaying the amount of liquid in a tank, the amount of water in the tank and the velocity of sound through the liquid in the tank is described with special application to a buried tank containing gasoline with the possibility of water in the bottom of the tank. The apparatus includes an ultrasonic transducer at a fixed distance above the bottom of the tank, a plurality of submerged reflectors vertically arranged at fixed distances above the transducer and a remote console, containing a computer, for activating the transducer and receiving signals of ultrasonic reflections developed by the transducer. Methods are disclosed utilizing the apparatus for computing the height of the liquid (gasoline) level, the depth of the water, if any, the velocity of sound through the gasoline and through the liquid as a whole, and for computing average temperature of the liquid in the tank.

Abstract: A liquid boundary level detector employing an open-ended conduit which directs pressure waves toward a liquid boundary layer. The conduit is moved from a starting position toward the liquid boundary and, upon contact with the boundary, there is a change in acoustic impedance within the conduit. This change is monitored and a signal is generated indicative of such contact. Once the initial liquid boundary position is determined, that may become the reference position for subsequent liquid boundary measurements or motions.

Abstract: Acoustic signals are transmitted through the fluid flow of a fuel delivery pump to a tank to be filled. From reflection signals the fluid level in the tank is detected and a timely disconnection of the pump can be effected in order to prevent fuel losses.

Abstract: An improved ultrasonic system for detecting the level of a material that has a surface, for example a liquid level inside of a tank, which improves the ability to detect levels particularly when the tank is nearly full. A transmitted ultrasonic signal from a transducer is reflected against the material in the tank, and when received back at the transducer, an output pulse is provided from the transducer. The distance or level is determined by determining the time between the transmission and the reflected signal. A comparator compares the signal from the transducer with a reference and provides an output when a pulse of greater magnitude than the reference is received.

Abstract: Multiple phase flow is detected and characterized in a fluid-containing conduit using a compressional wave acoustic transducer in the pulse-echo mode. The acoustic energy is transmitted in a transverse direction through the conduit and the returning echo is analyzed to determine if single or multiphase flow is present in the conduit.

Abstract: An ultrasound liquid level detector system for automatically controlling the dispensing of a post-mix beverage, including microprocessor-controlled circuitry for monitoring and implementing the automatic dispensing process. The microprocessor is interfaced with an ultrasonic transducer which transmits ultrasonic wave energy towards the container to be filled and receives reflected ultrasonic wave energy, the characteristics of which are analyzed within the microprocessor to implement control functions of the automatic dispensing process. Dispensing is initially stopped before the liquid level reaches the top of the container to allow for dissipation of foam on the top of a carbonated beverage and dispensing is reinitiated to top off the level of beverage adjacent the top of the container. The disclosed system also utilizes the ultrasonic transducer to measure the level of ice within the container prior to dispensing and precludes dispensing of the beverage if the level of ice exceeds a predetermined limit.