US3580092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic flowmeter
Assignee: SCARPA LAB Inc
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Filing: 1969-12-23
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Granted: 1971-05-25
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Expires: 1989-12-23
Abstract
Abstract A clamp-on flowmeter having a pickup element designed to be removably secured on an external surface of a pipe, which is responsive to ultrasonic radiation generated by shear action of fluid flowing in the pipe. The signal from the pickup element is filtered, frequency-selectively amplified, and integrated, the output being used to operate indicating means, and various types of relay-actuated devices. In one embodiment, the pickup element is a piezoelectric wafer; and the response characteristic for the overall circuit including the pickup element is designed to be fairly uniform over a broad range of frequencies extending from just above the audio range to at least about 100 kilocycles. In a modification of this, the pickup element is designed to respond to a relatively narrow band of frequencies well above the audio range, to which band the amplifier-integrator circuit is specifically tuned.
Inventors
- 👤 Thomas J Scarpa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:53
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/02; G01N29/032; G01F; G01F1/00; G01F1/66; G01F1/666; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02836
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
156 words
A device for monitoring fluid flow in a pipe which comprises in combination a transducer constructed to respond to at least a portion of the signals generated by the shearing action of said fluid flow within a broad spectrum of frequencies extending from the audio range to at least beyond 100 kilocycles, said transducer being mounted in a housing including means mechanically connected to said housing for coupling said transducer in ultrasonic transfer relation with an external surface of said pipe devoid of specialized fittings for said coupling, a circuit electrically coupLed to derive an output signal from said transducer, said circuit including mans for frequency-selectively amplifying and filtering the output signal derived from said transducer within a preselected frequency range and bypassing signals below said range, and for integrating the steady state component of said signal while rejecting transient signals, and means connected to said circuit for utilizing the output current derived from said circuit.
Claim 2
Independent Claim
156 words
A device for monitoring fluid flow in a pipe which comprises in combination a transducer constructed to respond to at least a portion of the signals generated by the shearing action of said fluid flow within a broad spectrum of frequencies extending from the audio range to at least beyond 100 kilocycles, said transducer being mounted in a housing including means mechanically connected to said housing for coupling said transducer in ultrasonic transfer relation with an external surface of said pipe devoid of specialized fittings for said coupling, a circuit electrically coupLed to derive an output signal from said transducer, said circuit including mans for frequency-selectively amplifying and filtering the output signal derived from said transducer within a preselected frequency range and bypassing signals below said range, and for integrating the steady state component of said signal while rejecting transient signals, and means connected to said circuit for utilizing the output current derived from said circuit.
Claim 3
Dependent Claim
60 words
The combination in accordance with claim 1 wherein the low frequency cutoff point of said preselected frequency range lies between 200 cycles per second and 40 kilocycles per second, and wherein the response characteristic of said circuit is a substantially uniform plateau between said low frequency cutoff point and a high frequency cutoff point of at least about 100 kilocycles.
Claim 4
Dependent Claim
106 words
The combination in accordance with claim 2 wherein said circuit includes: at least one preamplifier stage including means for selectively amplifying high frequency signals and bypassing low frequency signals, high pass band filtering means connected to said preamplifier stage, at least one additional amplifier stage connected to said filtering means for receiving and selectively amplifying the output of said filtering means by selecting the high frequencies and bypassing the low frequencies, and integrating means comprising a charging circuit, having a time constant between one-tenth second and 10 seconds constructed to receive and integrate the steady response from said last-named amplifying means and to reject the transients.
Claim 5
Dependent Claim
22 words
The combination in accordance with claim 3 wherein said charging circuit has a time constant of between one-half second and 2 seconds.
Claim 6
Dependent Claim
31 words
The combination in accordance with claim 3 wherein the voltage output of said integrating circuit is substantially an inverse square function of the rate of fluid flow in said pipe section.
Claim 7
Dependent Claim
37 words
The combination in accordance with claim 1 wherein said circuit including said transducer is tuned to respond sharply to frequencies within the range 90 to 100 kilocycles per second, and to be substantially unresponsive to other frequencies.
Claim 8
Dependent Claim
68 words
The combination in accordance with claim 1 wherein said transducer is rigidly mounted to the inner face of the base of said housing, and said means for coupling said transducer in ultrasonic transfer relation with an external surface of said pipe includes a metal strap constructed to be secured around the periphery of said pipe section for coupling the base of said housing to said external pipe surface.
Claim 9
Dependent Claim
38 words
The combination in accordance with claim 7 wherein said means for coupling said transducer includes a curvilinear portion contiguous with the base of said transducer housing, and constructed to substantially conform to the contour of said pipe section.
Claim 10
Dependent Claim
15 words
The combination in accordance with claim 8 wherein said curvilinear portion comprises a metal member.
Claim 11
Dependent Claim
17 words
The combination in accordance with claim 8 wherein said curvilinear portion at least partially comprises nonmetal material.
Claim 12
Dependent Claim
20 words
The combination in accordance with claim 1 wherein said means for utilizing the said output current comprises an indicating meter.
Claim 13
Dependent Claim
18 words
The combination in accordance with claim 1 wherein said means for utilizing said output current comprises recording means.
Claim 14
Dependent Claim
33 words
The combination in accordance with claim 1 wherein said means for utilizing said output current comprises a relay for actuating additional functions including valve means for controlling the fluid flow in said pipe.
Claim 15
Dependent Claim
19 words
The combination in accordance with claim 1 wherein said means for utilizing said output current comprises an alarm device.
Claim 16
Independent Claim
96 words
The method of monitoring fluid flow in a pipe which comprises the steps of securing a transducer in ultrasonic energy translation with an external surface of said pipe section whereby said transducer is responsive to the signal generated by the shearing action of fluid flowing in said pipe, frequency-selectively amplifying and filtering the output signal derived from said transducer to produce a substantially uniform response profile within a preselected frequency range, while rejecting signals below said frequency range, integrating the steady state component of said amplified signal while rejecting transients, and utilizing the said integrated output.
Claim 17
Independent Claim
96 words
The method of monitoring fluid flow in a pipe which comprises the steps of securing a transducer in ultrasonic energy translation with an external surface of said pipe section whereby said transducer is responsive to the signal generated by the shearing action of fluid flowing in said pipe, frequency-selectively amplifying and filtering the output signal derived from said transducer to produce a substantially uniform response profile within a preselected frequency range, while rejecting signals below said frequency range, integrating the steady state component of said amplified signal while rejecting transients, and utilizing the said integrated output.
Claim 18
Dependent Claim
45 words
The method in accordance with claim 15 wherein said preselected frequency range has a low cutoff point between about 200 cycles per second and about 40 kilocycles, and a fairly uniform response therefrom to a high frequency cutoff point of at least about 100 kilocycles.
Claim 19
Dependent Claim
119 words
The method in accordance with claim 16 wherein the signal output from the transducer is passed through at least one preamplification step in which the high frequency signals within said range are amplified, and the low frequency signals are bypassed, the output from said preamplification step is passed through an additional high pass filtering step, the output from said filtering step is further amplified by receiving and selectively amplifying the high frequencies and bypassing the low frequencies, the steady state component of the output from said further amplification step is integrated in a charging circuit having a time constant between about one-half second and 2 seconds for rejecting transients, and the integrated output is utilized for actuating additional circuitry.
Claim 20
Dependent Claim
29 words
The method in accordance with claim 15 wherein said preselected frequency range is between about 90 and 100 kilocycles, and wherein said circuit is sharply tuned to said range.
Claim 21
Dependent Claim
53 words
The method in accordance with claim 15 which comprises the step of coupling said transducer in ultrasonic energy translation with a pipe surface devoid of specialized external fittings for said coupling by securing a metal strap around the periphery of said pipe to hold the transducer in close relation to said pipe surface.
Claim 22
Dependent Claim
21 words
The method in accordance with claim 19 which comprises contouring the bottom of the transducer housing to fit the pipe surface.
Claim 23
Dependent Claim
39 words
The method in accordance with claim 15 wherein said integrated output is utilized to perform at least one of a plurality of functions including indicating, recording, controlling the fluid flow in said pipe, and actuating alarm and safety devices.
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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |