Speed Of Sound Compensation Patents (Class 367/902)
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Patent number: 4949321Abstract: An ultrasound echo profile sensor for use as a tactile sensor, having an ultrasound measuring head containing a transmitter and a receiver and also having an entrained reference reflector by means of which the current speed of sound of the ambient air can be identified. The respective distance of the tactile sensor from a sensor subject can be correctly measured independently of the variable speed of sound of the ambient air because a reference echo caused by the reference reflector can be discriminated from situation echoes on the basis of its known, proximate position. The reference reflector, whose distance from the ultrasound receiver is constant in the reference case, is arranged such that the distance between the ultrasound receiver and the reference reflector changes in a characteristic way given tactile contact between a sensor head and the sensor subject, particularly a workpiece.Type: GrantFiled: September 30, 1987Date of Patent: August 14, 1990Assignee: Siemens AktiengesellschaftInventor: Valentin Magori
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Patent number: 4942558Abstract: An ultrasonic ground speed sensor has a single transducer which both transmits and receives ultrasonic signals. The sensor is mounted on a vehicle in alignment with the direction of the vehicle, the transducer having a built-in angle with the body of the sensor unit. The transmitted signal is clocked by a 16 MHz clock, with the signal received by the transducer selectively filtered and amplified. A temperature sensor is also used to determine the speed of the transmitted and received signal. A 64-cycle sample period is used, as well as multiple counters and a signal processor to increase accuracy and minimize erroneous readings. A drop-out detector and monitoring system sensor is also described. The vehicle speed is calculated from a Doppler-based formula as a function of both the sum and difference of the transmitted and received signal frequencies. Also disclosed is a gasket seal having leak holes for drainage from the interior of the sensor.Type: GrantFiled: March 31, 1988Date of Patent: July 17, 1990Assignee: Micro-Trak Systems, Inc.Inventors: Thomas K. Hiniker, Semor D. Tofte
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Patent number: 4935884Abstract: An apparatus for determining the length of an open or closed-end pipe by measuring the propagation delay of a sound pulse transmitted down the pipe bore. The apparatus includes an acoustic transducer, an acoustic detector and associated circuitry for computing the time required for an acoustic pulse to travel and return the length of a pipe. Electronic circuitry, including a microprocessor, is employed to provide the apparatus with an automatic gain adjustment feature. The gain circuitry increases the amplification until a return pulse of desired amplitude is obtained. The gain is time varying to make the last-to-return signals strongest thereby avoiding false readings from pipe discontinuities. Compensation is made for speed-of-sound variations due to temperature, humidity, and barometric pressure by direct measurement of speed of sound during each length measurement. The open or closed endedness of a pipe is determined by return signal charateristics and a correction factor applied for open-ended pipe.Type: GrantFiled: April 28, 1988Date of Patent: June 19, 1990Assignee: Champlin Electronics, Inc.Inventor: David J. Hajicek
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Patent number: 4930350Abstract: An apparatus and method for measuring the length of a tubular body. The apparatus comprises: a transmitter (10) positioned at first end of the tubular body (12) for transmitting an acoustical signal along the interior of the body (12), a reflecting medium (14) provided at the other end of the body (12) for reflecting the transmitted acoustical signal, acoustical receivers (26, 28) for measuring the period of time for the signal to be transmitted along the body (12) from the transmitter (10) to the second end of the body (12) and be reflected back to the first end, acoustical receivers (26, 28) provided along the central axis of the body (12) for measuring the speed of sound therein, and, circuitry (42, 44) for calculating and displaying the length of the body (12) as a function of the period of time and speed of sound in the body (12).Type: GrantFiled: October 6, 1988Date of Patent: June 5, 1990Inventors: Robert Bode, Harlan L. Nicholson
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Patent number: 4914641Abstract: An ultrasonic measuring transducer system in which an ultrasonic transducer transmits an ultrasonic pressure wave and receives a return echo from a target and an electronic circuitry means converts the received pulses to arrange information to a target. The ultrasonic transducer is mounted in a wall of a plenum chamber. Air flow passages or apertures surround the ultrasonic transducer and air from a supply under pressure is connected to said plenum chamber. A temperature (or velocity of sound) measuring device is mounted in the plenum chamber for measuring the temperature from which the speed of sound in the medium is determined, and a measuring chamber forming tube surrounding the transducer and air outlet apertures provide a space in which air flow is maintained at a relatively constant rate and the temperature in substantially all of the measuring path and space between the target and said ultrasonic transducer is essentially the same as in the plenum chamber.Type: GrantFiled: November 10, 1988Date of Patent: April 3, 1990Assignee: Xecutek CorporationInventor: John A. Dorr
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Patent number: 4901292Abstract: A method for the position detection of the strip edge of a material web by means of an ultrasonic detector disposed in the strip edge region uses a transmitter 2 and a receiver 3, the received sound waves being transformed into an electric signal. To be sure to eliminate the influence of reflected waves on the measurement result, the transmitter 2 emits mutually time-shifted single pulses or wave packets. The wave packet (or single pulse) received by the receiver 3 is transformed into a corresponding electric oscillation packet, a limited area of the oscillation packet is scanned and the scan value is stored for further processing. An arrangement for the performance of the method comprises the transmitter 2 which is fed by a pulse train generator 4 the receiver 3 for delivering an electrical signal, an activatable peak rectifier circuit 6 connected to the receiver and an activatable transmission circuit 9 connected to the rectifier for transmission of the peak value to a memory.Type: GrantFiled: July 11, 1986Date of Patent: February 13, 1990Assignee: AEG AktiengesellschaftInventor: Hans-Joachim Schrauwen
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Patent number: 4868797Abstract: 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.Type: GrantFiled: September 23, 1987Date of Patent: September 19, 1989Assignee: Fischer & Porter CompanyInventor: Daniel J. Soltz
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Patent number: 4833660Abstract: 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.Type: GrantFiled: October 14, 1987Date of Patent: May 23, 1989Assignee: Office National d'Etudes et de Recherches AerospatialesInventors: Alain Deom, Jean-Claude Garnier, Didier Guffond
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Patent number: 4769793Abstract: An ultrasonic transducer and method for detecting the distance to an object using ultrasonic energy. The transducer includes a foil which creates ultrasonic energy. First and second reference surfaces are provided which are spaced between the transducer and the object. The two reference surfaces provide for immunity against temperature and positional changes.Type: GrantFiled: February 12, 1986Date of Patent: September 6, 1988Assignee: Ultrasonic Arrays, Inc.Inventors: James N. Kniest, James M. Hossack, Walter Lecoque
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Patent number: 4762001Abstract: For identifying the position of a movable body comprising a reflector, a primary transducer and a secondary transducer are utilized which transmit ultrasonic pulses to the reflector and, in turn, detect the ultrasonic pulses reflected by the reflector. A measuring device identifies a positional value assigned to the position of the reflector from the transit times of the ultrasonic pulses from both transducers. To this end, the measuring equipment has a primary control to which a calculator, a primary memory, a timer and a pilot control are coupled. Furthermore, the measuring equipment has a receiver, a transmitter and a transfer device which alternately connects the ultrasonic transducers to the measuring equipment.Type: GrantFiled: June 26, 1987Date of Patent: August 9, 1988Assignee: Siemens AktiengesellschaftInventor: Gero Wuttke
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Patent number: 4762425Abstract: Measurements of the times of flight of sound waves can be used to determine temperature in a gas contained in a long tube which confines sound waves. Sound pulses are transmitted and received by a suitable loud speaker attached to one end of the long tube. A number of stubs or other discontinuities produce the sound reflections whose times of arrival are measured. The time intervals yield average sound speeds in each interval between any two stubs from which temperatures are calculated. Corrections for thermal expansion of the tube are easily made.Type: GrantFiled: October 15, 1987Date of Patent: August 9, 1988Inventors: Parthasarathy Shakkottai, Shakkottai P. Venkateshan
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Patent number: 4745808Abstract: Measurement apparatus utilizes a sonar head for sending and receiving sonar signals and the apparatus is calibrated before each measurement by locating the sonar head a fixed, predetermined distance from a stationary target. Movement of the sonar head is accomplished by a stepper motor and lead screw arrangement to position the sonar head the same, predetermined distance from the element to be measured as it was originally placed for calibration, and the difference between the calibration distance and the second distance is from a target motor and lead screw arrangement to position the sonar head the same, predetermined distance from the element to be measured as it was originally placed for calibration, and the difference between the calibration distance and the second distance is translated into a distance representing the desired measurement.Type: GrantFiled: December 15, 1986Date of Patent: May 24, 1988Inventor: John H. Hagen
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Patent number: 4735088Abstract: An acoustic inspection system includes acoustic transducers to transmit and receive continuous acoustic waves at a constant frequency. Changes in phase and/or amplitude of acoustic waves reflected at different times from a fixed reference target through an isothermal transmission medium are detected. The temperature of the acoustic transmission path is controlled in response to the detected phase changes to maintain the wavelength of acoustic waves constant independent of changes in humidity and barometric pressure.Type: GrantFiled: September 18, 1986Date of Patent: April 5, 1988Assignee: Cochlea CorporationInventors: James A. Pinyan, B. Shawn Buckley, Kenneth L. Blanchard
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Patent number: 4719605Abstract: A self-calibrating ultrasonic distance sensing method and apparatus are disclosed in which a transducer periodically transmits a pair of bursts of acoustic energy along an acoustic path toward a target object. Echoes of the first acoustic burst in the burst pairs from a reference target at a known distance from the transducer are used for calibration purposes, and echoes of the second acoustic bursts in the pairs are used to determine distance to the target object.Type: GrantFiled: December 13, 1984Date of Patent: January 12, 1988Assignee: Honeywell Inc.Inventors: Kenneth C. Eder, Christos M. Koukovinis
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Patent number: 4679175Abstract: An ultrasonic distance sensing method and apparatus are disclosed in which a transducer periodically transmits a pair of bursts of acoustic energy along an acoustic path toward a target object, an echo of the first acoustic burst in each burst pair is used to establish a peak reference level, and an echo of the second burst in each pair is used to determine distance to the target object only if its level exceeds a predetermined fraction of the peak reference level.Type: GrantFiled: December 13, 1984Date of Patent: July 7, 1987Assignee: Honeywell Inc.Inventors: Kenneth C. Eder, Robert V. Krzyanowski
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Patent number: 4661933Abstract: An apparatus and method for the measuring the transverse dimensions of a hole such as in an oil well including a sonde on which an electro-acoustic transducer is mounted in an offcentered position in relation to the axis of the sonde. This transducer has two opposite active faces so as to simultaneously transmit acoustic pulses in diametrically opposite diections from the sonde. When the sonde is centered in the hole, the transducer picks up the echoes retransmitted by the wall of the hole in the two directions, at different times. A recording is made of these times and preferably also of an indication of the amplitude of each of these echoes to obtain both a diameter measurement and an indication of the condition of the hole surface. Several transducers are provided, superposed and oriented along various diameters distributed around the axis of the sonde.Type: GrantFiled: December 17, 1982Date of Patent: April 28, 1987Assignee: Schlumberger Technology CorporationInventors: Bronislaw Seeman, Benoit G. L. Froelich
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Patent number: 4584676Abstract: An improved method and apparatus for measuring the length of an open pipe includes a sound transducer placed in spaced open air communication with the interior of the pipe at a selected end. A logic circuit is employed with the transducer for producing a square wave sound pulse that is directed at the pipe's selected end. An oscillator provides an ambient temperature modified count in accordance with the time required for the pulse to travel the length of the pipe and return. For compensating for error tending to be introduced because of the spacing of the impedance reflective surface at the far end of the pipe, a standoff device establishes such a distance between the transducer and the selected end of the pipe as to effect an adjustment in the duration of the oscillator count that corrects for the error.Type: GrantFiled: March 15, 1982Date of Patent: April 22, 1986Assignee: Measurement Systems, Inc.Inventor: John W. Newman
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Patent number: 4581726Abstract: In an ultrasonic distance measuring apparatus producing distance data representing a distance to an object by transmitting and receiving an ultrasonic wave, a sensor detects variation in the temperature and/or humidity of the atmosphere, and a compensator compensates for variation in propagation characteristic of the ultrasonic wave caused by the variation in the temperature and/or humidity respectively.Type: GrantFiled: April 25, 1983Date of Patent: April 8, 1986Assignee: West Electric Co., Ltd.Inventors: Hiroshi Makino, Hiroshi Iwata
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Patent number: 4576286Abstract: A system for sorting parts wherein a part to be sorted is irradiated with wave energy of a single frequency (or very narrow band of frequencies) which interacts with the part. Wave energy emanating from the part is sensed at many spatially separated places to generate an electric signal representative of a characteristic of the amplitude and phase of the detected wave energy at each place. The electric signal so generated is compared with a pre-established signal and any differences therebetween are determined to establish whether the part is within acceptable limits in terms of geometric characteristics, e.g., size, material characteristics and orientation. The part is then acted upon on the basis of the comparison.Type: GrantFiled: June 27, 1983Date of Patent: March 18, 1986Assignee: Cochlea CorporationInventors: Bruce S. Buckley, Edward M. Buckley, Roy H. Reichwein
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Patent number: 4561064Abstract: To determine if a pulsed beam system, typically an ultrasonic pulsed beam system, which is located externally of a motor vehicle is in operative condition, a transmitter (14) projects a beam to a fixed reflector (16) located on the vehicle, and one (19) of a group of timing stages (18; 19, 20, 21) evaluates the transit time to the reflector. If the transit time to the reflector is slightly less than a predetermined time interval (Tc), so that the threshold timing level (Tc) is passed, a first indication, for example a frequency at a first tone (f1), generated by an acoustic tone generator (30) is reproduced in a loudspeaker; if, then, an obstruction is sensed by the beam, and the distance between the transmitter (14) and the obstruction (17) which forms a reflecting object drops below a first predetermined distance represented by a time period (T2), a second one of the transit time stages responds, and, through logic gates (22-24, 28, 29) provides a second discrete output frequency (f2) in the loudspeaker.Type: GrantFiled: February 28, 1983Date of Patent: December 24, 1985Inventors: Gerhard Bruggen, Dieter Karr, Wolfgang Rottler
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Patent number: 4543649Abstract: An ultrasonic system is responsive to the relative position of a movable device within a fluid-filled structure. A transducer transmits ultrasonic signals from a location fixed within the structure to the device for reflection thereby and for picking up the reflected signals.Type: GrantFiled: October 17, 1983Date of Patent: September 24, 1985Assignee: Teknar, Inc.Inventors: Kenneth O. Head, Arthur E. Bollinger
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Patent number: 4510587Abstract: The method and arrangement contemplates transmitting externally triggered trigger pulses by means of a magnetostrictive line or conductor and such produces echo pulses. Displacement path and time oscillator pulses are counted by two counter groups, and there is computed from the counter state the velocity-corrected position of a measuring head. Consequently, with a higher measuring rate there can be appreciably increased the accuracy of the evaluation of the pulses delivered by the ultrasonic measuring system, there can be obtained further measuring data (velocity and acceleration) by means of the moving measuring head, and there is possible an absolute measurement. Additionally, the resolution of the measured displacement path or distance can be randomly selected by means of the frequency of the displacement path or distance oscillator.Type: GrantFiled: October 19, 1982Date of Patent: April 9, 1985Assignee: Maag Gear-Wheel & Machine Company LimitedInventor: Otto Schneider
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Patent number: 4494224Abstract: Method and apparatus for determining the length of a tubular member such as a pipe are disclosed. A burst of acoustical pulses are emitted from a sending unit and are received by a reference acoustical transducer and by a slave acoustic transducer. The slave transducer emits a return pulse which is used to compute the duration of the sound propagation interval between the ends of the pipe. A phase angle compensation factor is computed by measuring the phase shift of the signal received by the reference transducer with respect to the signal emitted by the master transducer.Type: GrantFiled: July 16, 1982Date of Patent: January 15, 1985Inventors: David J. Morrell, Donald G. DeVault, William K. Sands, Jr.
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Patent number: 4388708Abstract: A distance R to be measured is derived by measuring the spacing x.sub.m between a fixed transmitter Tx and a movable receiver Rx, and comparing this with the reference spacing x.sub.ref between a fixed transmitter Tx' and receiver Rx. Each spacing is measured by passing a large number of pulses sequentially from receiver to transmitter through a coupling medium, the receipt of one pulse triggering transmission of the next. The spacing is derived from the time T taken to pass n pulses; preferably n is fixed and T is measured.Type: GrantFiled: March 18, 1981Date of Patent: June 14, 1983Inventors: Damir M. J. Skrgatic, John S. Strachan
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Patent number: 4381144Abstract: An underwater photographic system which includes an underwater camera enclosure having an underwater sonar range-finding apparatus for providing a signal to adjust the distance-related parameters of a camera enclosed therein. The enclosure is adapted to house typically an unaltered commercially available self-developing or "instant" camera specifically including a camera having an air-sonar range-finding device.Type: GrantFiled: July 15, 1981Date of Patent: April 26, 1983Inventor: Lloyd Breslau
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Patent number: 4358835Abstract: The reflector of an acoustic echo ranging system is matched so as to make up for the influence of the temperature at the bottom of the reflector, on the measurement of the back-reflected signal. The acoustic signal receiver being stationary the transmission frequency is controlled by a temperature responsive electronic circuit so that the receiver is always located at the same pressure antinode. Alternatively, the transmission frequency being fixed, the position of the receiver is controlled by a temperature responsive mechanical gear causing the position of the receiver to coincide with the same pressure antinode.Type: GrantFiled: December 22, 1980Date of Patent: November 9, 1982Assignee: Bertin & CieInventor: Jean-Michel Fage
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Patent number: 4317184Abstract: A circuit providing a ramp signal having dual slopes of increasing and decreasing magnitude is controlled to provide one of its ramp portions with a slope which varies in accordance with a signal perturbing effect and the other of which is constant. The dual slope ramp duration is modified in proportion to the perturbing effect and is used to compensate therefor.Type: GrantFiled: October 23, 1980Date of Patent: February 23, 1982Assignee: NP Industries, Inc.Inventor: Nicholas G. Leszczynski
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Patent number: 4261579Abstract: To determine the position of a bullet relative to a target an array of at least six transducers is provided, the transducers being in two parallel rows of three in a common plane. The instants of detection of the shock wave generated by the bullet are measured and the position of the bullet is calculated from the measured values.Type: GrantFiled: May 30, 1979Date of Patent: April 14, 1981Assignee: Australasian Training Aids (Pty.), Ltd.Inventors: William H. Bowyer, Robert Newnham
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Patent number: 4254478Abstract: In the measurement of the distance between two immersed points using ultrasonic signals, a control beacon is located at one point and a servo-beacon at the other point. The control beacon emits a first signal which is received by the servo-beacon. After a set period of time T sufficient for the disappearance of all echoes, the servo-beacon emits a signal which is received by the control beacon. Measurement apparatus associated with the control beacon determines the distance as a function of the time between emission of the first signal by the control beacon and reception of the signal from the servo-beacon, and the velocity of the ultrasonic signal which is determined in the region of the control beacon.Type: GrantFiled: June 22, 1979Date of Patent: March 3, 1981Assignee: Compagnie Francaise des PetrolesInventor: Jean-Claude Dumas
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Patent number: 4241430Abstract: An improved method and apparatus for determining the length of a tubular member from a selected end thereof utilizing a hand-held probe wherein means are provided for producing sound pulses at the selected end, means are provided for detecting sound pulses at the selected end, means are provided for sensing the ambient temperature of the air in the vicinity of the inside of the tubular member being measured, means are provided for determining the time elapsed from the moment the sound pulse is generated until the accoustic wave comprising the returning sound pulse is detected by the detecting means, and means are provided for compensating for the increased travel time of the sound pulse occasioned by the sound pulse being reflected from the impedance differential surface set up by the other end of the pipe and spaced from the other end of the pipe.Type: GrantFiled: January 8, 1979Date of Patent: December 23, 1980Assignee: Douglas J. KayemInventors: Douglas J. Kayem, Harold L. Reed
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Patent number: 4238844Abstract: A device which detects a displaced position by generating an ultrasonic signal in a magnetostrictive wire and measuring the propagation time of the signal generated. The device includes an exciting means to generate an ultrasonic signal in a magnetostrictive wire, first and second receiving means to receive the ultrasonic signal generated in the magnetostrictive wire by the exciting means, a means for changing the distance between the exciting means and each of the first and second receiving means in accordance with a mechanical displacement, and a circuit means for producing a signal representative to the time periods required for the generated ultrasonic signal to reach the first and second receiving means.Type: GrantFiled: February 23, 1979Date of Patent: December 9, 1980Assignee: Yokogawa Electric Works, Ltd.Inventors: Toshitsugu Ueda, Seiki Ra, Masanori Noguchi
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Patent number: 4221004Abstract: An ulrasonic liquid level measurement device is used to measure the depth of a flowing liquid in a channel using an ultrasonic transducer that is positioned out of contact with the liquid and above and directed toward the channel. An ultrasonic burst is directed toward the channel and the reflected echo from the surface of the liquid is returned and sensed by the transducer. The transit time of ultrasonic transmission and echo return is indicative of the liquid level. An adjustable discriminator is provided to specify a maximum liquid level in the channel and a minimum liquid level, which, typically is the floor of the channel. The maximum and minimum levels are adjustable to accomodate variable channel configurations and transducer mounting arrangements. Automatic adjustment is provided to compensate for different cable lengths which may be used to connect the ultrasonic transducer to the transducer driver and receiving section.Type: GrantFiled: August 3, 1978Date of Patent: September 2, 1980Assignee: Robertshaw Controls CompanyInventors: Charles M. Combs, Perry H. Goodwin, Jr.
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Patent number: 4210969Abstract: An improved sound ranging system increases the precision of range measurement by automatically correcting for any variation in the velocity of sound in the medium. The automatic correction for the sound velocity utilizes a small sound reflecting target located at a precise fixed distance from the transducer surface. A digital circuit, including a microcomputer, improves the measurement accuracy of the system. The invention includes a time delay and sensitivity control in one of the two time measurement circuits employed in the system to prevent "ghost" signals caused by multiple round-trip target reflections from introducing errors in the range measurements.Type: GrantFiled: March 13, 1978Date of Patent: July 1, 1980Assignee: The Stoneleigh TrustInventor: Frank Massa