| 序号 | 专利名 | 申请号 | 申请日 | 公开（公告）号 | 公开（公告）日 | 发明人 |
|---|---|---|---|---|---|---|
| 561 | Direct measurement ultrasonic velocity measuring system | US347282 | 1994-11-30 | US5557536A | 1996-09-17 | Frederick A. Nabity; Larry L. Fritz; Douglas T. Carson |
| To determine the average velocity of a fluid stream, an ultrasonic signal is transmitted into the fluid and reflected ultrasonic signal received. The signals are mixed with a frequency of the transmitted ultrasonic signals. A Fourier transform is performed on the signals, the largest coefficient used to normalize the signal and certain of the weighted signals are averaged. | ||||||
| 562 | Device for gauging the level of a fluid | US170305 | 1994-03-02 | US5543720A | 1996-08-06 | Kurt O. Edvardsson |
| A device for gauging the level of a fluid in a container is described. It comprises a transmitter for transmitting a polarizable microwave signal through a first waveguide section, a receiver for receiving a reflected microwave signal, an electronic unit for determining the reflex position of the reflected microwave signal and an antenna means with a second waveguide section. The device is primarily characterized in that the transmitter and receiver, respectively, transmits and receives a waveguide mode each, mutually orthogonal, and by an easily replaceable third waveguide section (6, 16, 17) inserted between the first (2) and second (5) waveguide sections, provided with means (12, 14, 15, 22) for polarization and/or damping for optimal adaptation of the device to various containers and antennae. | ||||||
| 563 | Ultrasonic level instrument with dual frequency operation | US164368 | 1993-12-09 | US5452611A | 1995-09-26 | Lawrence Jones; Alexander J. Esin; Boris S. Rosselson |
| An ultrasonic level instrument detects the presence of a fluid at a defined location and provides a self-diagnostic integrity check. An excitation circuit simultaneously induces vibrations at a first and second frequency in a transmitting piezoelectric crystal, and the vibrations are detected by a receiving crystal. A first and second filter circuit generate first and second filter outputs, respectively, by selectively passing the receiving crystal output at the first and second frequencies, respectively. The first filter output is indicative of the presence of fluid and the second filter output is indicative of the sensor integrity. | ||||||
| 564 | Process for measuring the level of fluid in a tank according to the radar principle | US132047 | 1993-10-05 | US5438867A | 1995-08-08 | Ronald van der Pol |
| A process for measuring the level of a liquid in a tank according to the radar principle, in which microwave energy is transmitted in the direction of the liquid level and the bottom of the tank from an antenna located above the liquid level, a measuring signal reflected from the liquid level is received by an antenna, and the liquid level may be determined from the transit time of the measuring signal, other signals than the measuring signals, i.e., spurious signals, in particular a bottom signal reflected on the bottom and which is usually relatively strong, being filtered out or otherwise taken into account by the measuring technique, and the actual distance between the antenna and the bottom of the tank (the actual bottom distance), being known, and the permittivity and permeability numbers for the liquid in the tank being at least approximately known, leads to reliable results in a way which is simpler with respect to analysis technique because of the fact that the transit time is determined for the bottom signal and an apparent bottom distance is determined from this transit time, and that from the ratio of the determined apparent bottom distance and the known actual bottom distance, the ratio of apparent to actual liquid level, and therefore the actual liquid level, is determined. | ||||||
| 565 | Method of and device for fluid surface detection using an ultrasonic transducer | US917205 | 1992-07-20 | US5428997A | 1995-07-04 | Mark T. Paulsen |
| The present invention provides a method of detecting a fluid surface and a circuit for an ultrasonic transducer for detecting such a fluid surface. In accordance with the method, an ultrasonic transducer driver generates a first voltage proportional to the resonant frequency of the ultrasonic transducer. A reference voltage is generated and the reference voltage and the first voltage are monitored and compared, and a surface detect signal is generated when the first voltage drops below the reference voltage. The circuit of the invention includes means for generating a first voltage proportional to the resonant frequency of the transducer, means for generating a reference voltage, and a comparator for monitoring the first and reference voltages and generating a surface detect signal when the first voltage drops below the reference voltage. | ||||||
| 566 | Ultrasonic transducer assembly for measuring liquid level | US152997 | 1993-11-12 | US5410518A | 1995-04-25 | Robert E. Birkett |
| A transducer assembly for an ultrasonic liquid level measuring device utilizing a piezoelectric crystal for generating ultrasonic pulses to be transmitted through a volume of liquid. The assembly includes an enclosure for the piezoelectric crystal assembly, that defines an interior space and a sealed opening for a cable. The enclosure is provided with a metallic layer that shields the entire interior space from electromagnetic interference. The assembly also includes a crystal housing assembly and a terminal block all located within the sealed enclosure. | ||||||
| 567 | Ultrasonic fuel gauging system using state machine control | US42291 | 1993-04-02 | US5400376A | 1995-03-21 | Christian L. Trudeau |
| Ultrasonic fuel gauging apparatus for a fuel tank having a plurality of ultrasonic fuel level sensors for sensing fuel levels at respective predetermined locations in a tank based on echo ranging; a memory means for storing sensor data; and a state device for interrogating each of the sensors by controlling the application of transmit pulses to each of the sensors and for receiving output signals corresponding to return echoes, the state device operating in response to a sequential state counter. | ||||||
| 568 | Surface separator and dispersion apparatus | US66045 | 1993-05-25 | US5397460A | 1995-03-14 | John Koblanski |
| An apparatus to separate two immiscible liquids of different densities that form a two phase mixture comprising an upper layer (10) and a lower layer (12) when together. The apparatus has a main body (14) to receive the two liquids. The main body has a base and an open top. There is an outlet (20) adjacent the base of the main body, arranged tangentially. A pump (22) pumps liquid from the main body through the outlet (20). A jet (24) generally adjacent the center of the main body (14) directs liquid upwardly from the body. The liquid is supplied to the jet (24) by pump (22). Floats (30) allow floating of the apparatus in a mixture of the two liquids. The fluid driven from the outlet (22) draws the two liquids into the body and the liquid from the jet (24) forces the upper layer (10) of liquid upwardly to separate the two liquids. | ||||||
| 569 | Liquid-level gauging | US26767 | 1993-03-05 | US5309763A | 1994-05-10 | David Sinclair |
| An ultrasonic liquid-level sensing system has a sensor with a number of reflectors mounted one above the other along the length of a tube that extends upwardly from a transducer and is filled with liquid to the same height as outside the tube. Liquid height is calculated from the difference between the arrival times of the pulses reflected from the two uppermost submerged reflectors and the difference between the arrival times of pulses reflected from the surface of the liquid and the uppermost submerged reflector. | ||||||
| 570 | Measuring device and process for determining the fill level in fluid containers, preferably for tank installations, with a sound waveguide | US840746 | 1992-02-24 | US5226320A | 1993-07-13 | Johannes Dages; Martin Ruttel |
| In a level measuring device for containers filled with fluid, preferably tanks in tank installations, the fill level height h is determined from the transit time of ultrasound pulses which are emitted by first sound pulse transmitters along a main measuring path extending from the bottom region of the tank to the fluid surface and are reflected from the fluid surface to first sound pulse receivers. Temperature sensors are provided for finding the temperature distribution throughout the fill level height h. Processing the measurements provides a mean temperature TM in the fluid volume. In addition to the main measuring path there is a reference path in the fluid volume, with second sound pulse transmitters and receivers and a reference temperature sensor for measuring a reference temperature T.sub.Ref. The reference path makes it possible to find the sound velocity v*(T.sub.Ref) in the fluid volume at the reference temperature T.sub.Ref from the measured difference in transit time, so that a temperature-corrected sound velocity v(T) in the fluid volume: v(T)=v*(T.sub.Ref)[1+K.sub.k.multidot..DELTA. T], and thus a temperature-corrected fill level height h(T)=v(T).multidot.t.sub.H, are found, in which .DELTA.T=TM-T.sub.Ref, and K.sub.k is a medium-dependent correction factor. The measuring device and a process for determining the fill level use a measuring tube with first and second sound waveguides. | ||||||
| 571 | Material level indicating apparatus with status light and external test features | US843386 | 1992-02-28 | US5223819A | 1993-06-29 | Norman F. Marsh; Robert T. Eichberger |
| Apparatus for indicating level of material in a vessel that includes a probe for placement in the vessel at a position corresponding to a desired height at which material level is to be detected. Electronic circuitry is coupled to the probe, and is responsive to operating characteristics of the probe for sensing a change of such operating characteristics between a first operating characteristic at which material is spaced from the probe, and a second operating characteristic when material is adjacent to the probe. The electronic circuitry is contained within a closed housing mounted on the probe, and is connected to a source of electrical power positioned remotely of the vessel. A pair of status lamps are positioned on the housing, and are coupled to the electronic circuitry for respectively indicating application of electrical power to the circuitry and detection of one or the other of the operating characteristics at the probe. A reed switch is positioned within the housing, and is responsive to juxtaposition of a magnet externally of the housing for simulating one of the operating characteristics of the probe independently of actual material level at the probe. | ||||||
| 572 | Monitoring film fouling in a process stream with a transparent shunt and light detecting means | US754016 | 1991-09-03 | US5185533A | 1993-02-09 | Rodney H. Banks; Robert J. Wetegrove |
| Method and apparatus for determining accumulated film thickness at the inside diameter of a main stream conduit conducting a main stream of a flowing fluid by employing:a transparent shunt conduit to shunt from the main stream a sample stream of the process fluid,a reference light emitter and light detector at a reference section of the shunt where any appreciable film is removed, an upstream sample light emitter and detector opposed thereto,a common source of light so that respective emitters emit light beams of the same intensity, and means for determining concurrently analogs of light received by the detectors, whereby film thickness may be determined for the sample. | ||||||
| 573 | Device for level gauging with microwaves | US613574 | 1990-12-04 | US5070730A | 1991-12-10 | Kurt O. Edvardsson |
| 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. | ||||||
| 574 | Fiber optic liquid leak detector | US511618 | 1990-04-20 | US5058420A | 1991-10-22 | Victor Vali; David B. Chang; Patrick C. Brownrigg |
| A precision liquid leak detector 10 free of mechanical moving parts is disclosed herein. The liquid leak detector 10 of the present invention is disposed to measure the rate of change of the volume of a liquid within a container 14. The leak detector 10 includes a light guide 16, implemented as an optical fiber, which is disposed within the container 14 and at least partially immersed in the liquid. The optical fiber 16 includes a fiber core circumscribed by a fiber cladding selected such that evanescent wave loss occurs as a result of immersion of the cladding within the liquid. The optical fiber 16 is positioned in optical alignment with a laser source 26, which injects optical energy therein. The leak detector 10 of the present invention further includes an arrangement 24 for measuring the decrease in the intensity of the injected optical energy occurring over a length of the fiber 16 immersed in the liquid. The measuring arrangement 24 then generates an intensity loss signal indicative of this intensity decrease. The inventive leak detector 10 also includes a network 36 and 38 for measuring the rate of change of the intensity loss signal and for calculating the rate of change of the liquid volume on the basis of the change in the intesity loss signal. | ||||||
| 575 | Apparatus and method for providing a temperature compensated liquid level measurement | US453736 | 1989-12-20 | US5038611A | 1991-08-13 | Thomas P. Weldon; James L. McShane |
| A system for providing a temperature compensated measurement indicative of the height of a fluid in a vessel includes an acoustic waveguide in fluid communication with the vessel. A reference target is positioned within the waveguide. Ultrasonic signals are produced in the fluid and a timer measures a first transit time representative of the time for the ultrasonic signals to travel to and from the target and a second transit time representative of the time for the ultrasonic signals to travel to and from the surface of a fluid in the waveguide. A circuit calculates the height of the fluid in the waveguide from the first and second transit times. Another circuit determines the density of the fluid in the waveguide from the first transit time and normalizes the calculated height of the fluid based on the density of the fluid such that the normalized height is indicative of the height of the fluid in the vessel. | ||||||
| 576 | Circuit arrangement for self-excitation of a mechanical oscillation system to natural resonant oscillations | US455417 | 1989-02-27 | US5029268A | 1991-07-02 | Martin Pfandler |
| The circuit arrangement for self-excitation of a mechanical oscillation system to natural resonant oscillations includes an electromechanical transducer system which is arranged in the feedback circuit of an electronic amplifier circuit so that it is stimulated by the output AC voltage of the amplifier circuit to mechanical oscillations and furnishes an AC voltage with the frequency of the mechanical oscillations to the input of the amplifier circuit. The amplifier circuit has a non-linear gain characteristic which at small values of the input signal gives a greater amplification than at lower values of the input signal. As a result a reliable oscillation start is ensured even under unfavorable operating conditions while on the other hand the danger of erroneous indications of the oscillation state, for example due to external vibrations, is reduced. | ||||||
| 577 | Fluid level monitor | US425970 | 1989-10-24 | US5015995A | 1991-05-14 | Trevor J. Holroyd |
| 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. | ||||||
| 578 | Multi-level fiber-optic liquid-level sensing system | US418157 | 1989-10-06 | US4979797A | 1990-12-25 | Frank A. Nemeth |
| Plural sensor prisms and associated opticalfiber circuits are arrayed as a single vertical stem by which the individual prisms serve for response to each of a plurality of different liquid levels. Each prism is formed of light-transmitting plastic material which can be injection-molded to precision dimensions. The body configuration is such as to adapt to arrayed interconnection with tubular members, also of plastic, and bonded at telescoping fit of each prism to the tubular member or members to which it is connected. The prism configuration relied upon for sensed response to the presence of immersing liquid (as compared to air) is a solid region having an exterior profile which includes a downwardly convergent conical surface portion at least at spaced locales which are at equal but opposite offset from the cylindrical body axis, wherein the geometric apex angle of downward convergence is 90 degrees. As long as a given prism is exposed to air, a large amount of light is transmitted (by reflection within the prism) from a transmission optical fiber to a receiving optical fiber. But when immersed in a liquid, a portion of the light from the transmitting fiber is refracted into the liquid, resulting in a clearly detectable decrease in the amount of light coupled to the receiving fiber. | ||||||
| 579 | Optical sensor for detecting liquid medium | US285968 | 1988-12-07 | US4906845A | 1990-03-06 | Brian J. Bellhouse; Stephen Goodman |
| An optical sensor comprises a probe (10) and an annular optical element (13) coupled optically to a pair of optical fibres (18). Light transmitted down one fibre is reflected around the element (13) and back up the other fibre to a photodetector. The level of light received by the photodetector is dependent upon the amount of light lost from the element (13) as a result of characteristics of the surrounding medium. The presence or absence of a surrounding liquid medium may thus be sensed and a motor (34) operated to suck liquid up through the probe, when the liquid is present. | ||||||
| 580 | Optical fluid level sensor | US115304 | 1987-11-02 | US4878383A | 1989-11-07 | Walter J. Wiegand, Jr.; Robert H. Bullis |
| The present invention is related to a sight glass(10) that utilizes both reflected light at a glass to air interface(40) as well as the light transmitted through a glass to fluid to glass interface(44) to form a light pattern that is indicative of the true fluid level. By requiring that light always appear in either an "air" or "fluid" channel(42,46), any absence of light is assumed due to film coated surfaces or to other abnormal conditions. An absence of light is a signal that maintenance is required. | ||||||
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