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Patent US3697936A successfully refreshed from Google Patents.
US3697936A
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US
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Sound velocimeter
Assignee: Mesa Laboratories Inc
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Filing: 1970-02-27
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Granted: 1972-10-10
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Expires: 1990-02-27
Abstract
Abstract A sound velocimeter for measuring the velocity of sound in a fluid wherein the oscillator frequency is adjusted depending upon the relative position in time of the received signal with respect to the transmitted signal.
Inventors
- 👤 Ellis M Zacharias Jr
- 👤 Uldis Cirulis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:41
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/36; G01N29/38; G01N29/02; G01N29/024; G01N29/22; G01N29/222; G01N29/40; G01N2291/00; G01N2291/01; G01N2291/012
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
361 words
A velocimeter for measuring the velocity of sound in a fluid having at least one electroacoustic transducer and at least one reflector immersed in the fluid and placed such that the length of the sound path between the transducer and the reflector and return is fixed comprising: a free running oscillator; a divider-counter connected to the free running oscillator to produce a plurality of pulses; a trigger pulse logic circuit connected to the divider-counter to count the pulses and to generate a pulse when a predetermined pulse count is attained; a driver connected to the output of the trigger pulse logic circuit and the electroacoustic transducer such that when a pulse is received from the trigger pulse logic circuit an electrical pulse (transmit pulse) is applied to the transducer, the transducer converting the electrical pulse to a corresponding sound pulse which is transmitted to the reflector and returned therefrom to the transducer, the sound signal received by the transducer being converted into a corresponding electrical signal (received pulse); an r-f amplifier connected to the transducer to amplify the corresponding electrical signal; a gated peak detector connected to the r-f amplifier and adjusted so that it is on just prior to receiving the corresponding electrical signal; a d-c amplifier connected between the output of the gated peak detector and the driver to adjust the output amplitude of the driver in accordance with the amplitude of the received pulse; a threshold detector connected to the output of the r-f amplifier and adjusted such that it is on just prior to receiving the received pulse; a phase detector connected to the output of the threshold detector to detect the position of the received pulse in time with respect to the transmit pulse and to produce a d-c output proportional to the phase difference between the transmit pulse and the received pulse; the output of the phase detector being connected to the free running oscillator to thereby apply a voltage to the oscillator and change its frequency such that the received pulse will be applied to the phase detector a predetermined count prior to the generation of the pulse by the trigger pulse logic circuit.
Claim 2
Dependent Claim
361 words
A velocimeter for measuring the velocity of sound in a fluid having at least one electroacoustic transducer and at least one reflector immersed in the fluid and placed such that the length of the sound path between the transducer and the reflector and return is fixed comprising: a free running oscillator; a divider-counter connected to the free running oscillator to produce a plurality of pulses; a trigger pulse logic circuit connected to the divider-counter to count the pulses and to generate a pulse when a predetermined pulse count is attained; a driver connected to the output of the trigger pulse logic circuit and the electroacoustic transducer such that when a pulse is received from the trigger pulse logic circuit an electrical pulse (transmit pulse) is applied to the transducer, the transducer converting the electrical pulse to a corresponding sound pulse which is transmitted to the reflector and returned therefrom to the transducer, the sound signal received by the transducer being converted into a corresponding electrical signal (received pulse); an r-f amplifier connected to the transducer to amplify the corresponding electrical signal; a gated peak detector connected to the r-f amplifier and adjusted so that it is on just prior to receiving the corresponding electrical signal; a d-c amplifier connected between the output of the gated peak detector and the driver to adjust the output amplitude of the driver in accordance with the amplitude of the received pulse; a threshold detector connected to the output of the r-f amplifier and adjusted such that it is on just prior to receiving the received pulse; a phase detector connected to the output of the threshold detector to detect the position of the received pulse in time with respect to the transmit pulse and to produce a d-c output proportional to the phase difference between the transmit pulse and the received pulse; the output of the phase detector being connected to the free running oscillator to thereby apply a voltage to the oscillator and change its frequency such that the received pulse will be applied to the phase detector a predetermined count prior to the generation of the pulse by the trigger pulse logic circuit.
Claim 3
Dependent Claim
90 words
The invention of claim 1 wherein the phase detector comprises: a phase detection logic circuit for detecting the position in time of the received pulse and for producing a signal dependent on such time position; a detecting circuit connected to the phase detection logic circuit such that its output amplitude is proportional to the difference in time between the received pulse and the signal generated by the trigger pulse logic circuit; a phase detection d-c amplifier connected to the output of the detecting circuit and to the free running oscillator.
Claim 4
Dependent Claim
40 words
The invention of claim 2 including a phase lock threshold detector for detecting the amount of voltage applied to the free running oscillator by the phase detection d-c amplifier and a display connected thereto to show the voltage being applied.
Claim 5
Dependent Claim
38 words
The invention of claim 3 including a range selector connected to the free running oscillator for adjusting the frequency thereof and a logic circuit connected between the range switch and the threshold detector for controlling the operation thereof.
Claim 6
Dependent Claim
41 words
The invention of claim 4 including an absorption indicator connected to the driver for displaying the absorption in the fluid by measuring the amplitude of the pulse transmitted by the driver which is proportional to absorption of sound in the fluid.
Claim 7
Dependent Claim
38 words
The invention of claim 1 including a range selector connected to the free running oscillator for adjusting the frequency thereof and a logic circuit connected between the range switch and the threshold detector for controlling the operation thereof.
Claim 8
Dependent Claim
41 words
The invention of claim 1 including an absorption indicator connected to the driver for displaying the absorption in the fluid by measuring the amplitude of the pulse transmitted by the driver which is proportional to absorption of sound in the fluid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |