Patent US1183882A successfully refreshed from Google Patents.
US3713337A
Expired / Lapsed
US
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Apparatus and method for automatic differential pressure transducer range changing
Assignee: Daniel Industries Inc
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Filing: 1971-02-04
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Granted: 1973-01-30
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Expires: 1991-02-04
Abstract
Abstract In one exemplar embodiment, apparatus for automatic differential pressure transducer range changing is disclosed, utilizing a single differential pressure transducer the differential pressure measurement range of which may be changed merely by changing the characteristics of the electrical circuit generating a signal representative of the measured differential pressure and a signal level detector circuit to receive the output signal from the transducer and generate a signal the polarity of which changes in response to a change in level of the transducer output signal beyond a predetermined limit representative of a change in measurement range of the transducer. The Polarity-changing output signal of the detector circuit actuates a switching circuit to switch appropriate predetermined resistive elements into the transducer amplifier gain circuit to incrementally change the amplifier gain, and hence, the measurement range of the transducer.
Inventors
- 👤 L Stroman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:41
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/34; G01F1/36; G01F1/363
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
244 words
An apparatus for automatically measuring a plurality of ranges of differential pressure of a fluid flowing across a pressure head producing device within a pipeline, comprising a differential pressure transducer for measuring the differential pressure across the pressure head producing device, amplifier means cooperating with said transducer for generating a first electrical signal representative of said measured differential pressure within a first measurement range, signal level detector means for comparing the signal level of said first electrical signal against an electrical signal of predetermined level representative of one limit of said measurement range and generating a second electrical signal the level of which is indicative of whether the level of said first electrical signal is above or below said signal of predetermined level, circuit means responsive to said second electrical signal for generating a third electrical signal directly related to the level of said second electrical signal, relay means operable in response to said third electrical signal, variable gain means electrically interconnected with said amplifier means for changing the gain of said amplifier means between a gain appropriate to said first measurement range and a gain appropriate to a second measurement range in response to the operation of said relay means, and zeroing means electrically interconnected with said amplifier means for adjusting the electrical zero of said amplifier means when said amplifier means switches from said first measurement range to said second measurement range, said zeroing means operable in response to said relay means.
Claim 2
Independent Claim
244 words
An apparatus for automatically measuring a plurality of ranges of differential pressure of a fluid flowing across a pressure head producing device within a pipeline, comprising a differential pressure transducer for measuring the differential pressure across the pressure head producing device, amplifier means cooperating with said transducer for generating a first electrical signal representative of said measured differential pressure within a first measurement range, signal level detector means for comparing the signal level of said first electrical signal against an electrical signal of predetermined level representative of one limit of said measurement range and generating a second electrical signal the level of which is indicative of whether the level of said first electrical signal is above or below said signal of predetermined level, circuit means responsive to said second electrical signal for generating a third electrical signal directly related to the level of said second electrical signal, relay means operable in response to said third electrical signal, variable gain means electrically interconnected with said amplifier means for changing the gain of said amplifier means between a gain appropriate to said first measurement range and a gain appropriate to a second measurement range in response to the operation of said relay means, and zeroing means electrically interconnected with said amplifier means for adjusting the electrical zero of said amplifier means when said amplifier means switches from said first measurement range to said second measurement range, said zeroing means operable in response to said relay means.
Claim 3
Independent Claim
244 words
An apparatus for automatically measuring a plurality of ranges of differential pressure of a fluid flowing across a pressure head producing device within a pipeline, comprising a differential pressure transducer for measuring the differential pressure across the pressure head producing device, amplifier means cooperating with said transducer for generating a first electrical signal representative of said measured differential pressure within a first measurement range, signal level detector means for comparing the signal level of said first electrical signal against an electrical signal of predetermined level representative of one limit of said measurement range and generating a second electrical signal the level of which is indicative of whether the level of said first electrical signal is above or below said signal of predetermined level, circuit means responsive to said second electrical signal for generating a third electrical signal directly related to the level of said second electrical signal, relay means operable in response to said third electrical signal, variable gain means electrically interconnected with said amplifier means for changing the gain of said amplifier means between a gain appropriate to said first measurement range and a gain appropriate to a second measurement range in response to the operation of said relay means, and zeroing means electrically interconnected with said amplifier means for adjusting the electrical zero of said amplifier means when said amplifier means switches from said first measurement range to said second measurement range, said zeroing means operable in response to said relay means.
Claim 4
Independent Claim
244 words
An apparatus for automatically measuring a plurality of ranges of differential pressure of a fluid flowing across a pressure head producing device within a pipeline, comprising a differential pressure transducer for measuring the differential pressure across the pressure head producing device, amplifier means cooperating with said transducer for generating a first electrical signal representative of said measured differential pressure within a first measurement range, signal level detector means for comparing the signal level of said first electrical signal against an electrical signal of predetermined level representative of one limit of said measurement range and generating a second electrical signal the level of which is indicative of whether the level of said first electrical signal is above or below said signal of predetermined level, circuit means responsive to said second electrical signal for generating a third electrical signal directly related to the level of said second electrical signal, relay means operable in response to said third electrical signal, variable gain means electrically interconnected with said amplifier means for changing the gain of said amplifier means between a gain appropriate to said first measurement range and a gain appropriate to a second measurement range in response to the operation of said relay means, and zeroing means electrically interconnected with said amplifier means for adjusting the electrical zero of said amplifier means when said amplifier means switches from said first measurement range to said second measurement range, said zeroing means operable in response to said relay means.
Claim 5
Dependent Claim
91 words
An apparatus as claimed in claim 1, wherein said signal level detector means comprises a buffer amplifier for receiving said first electrical signal representative of said measured differential pressure within a first measurement range, and a differential amplifier having a first signal input of a predetermined level and receiving said first electrical signal from said buffer amplifier as a second signal input, said differential amplifier generating as an output said second electrical signal the level of which is directly related to the algebraic difference between said first and second signal inputs.
Claim 6
Dependent Claim
105 words
An apparatus as claimed in claim 2, wherein said variAble gain means comprises a plurality of variable resistors one side of each of which is commonly connected to a source of voltage, the other side of each of which is connected to one of a plurality of relay contacts, a relay switch cooperating with said contacts and being connected to a gain control circuit of said amplifier means, each of said variable resistors being set to a predetermined resistance for varying the gain of said amplifier means by a predetermined value when different ones of said variable resistors is connected with the amplifier means circuit.
Claim 7
Dependent Claim
100 words
An apparatus as claimed in claim 3, wherein said zeroing means comprises a plurality of variable resistors one side of each of which is commonly connected to a source of voltage, the other side of each of which is connected to one of a plurality of relay contacts, a relay switch cooperating with said contacts and being connected to a zeroing circuit of said amplifier means, each of said variable resistors being set to a predetermined resistance for changing the electrical zero of said amplifier means when different ones of said variable resistors is connected with the amplifier means circuit.
Claim 8
Dependent Claim
67 words
The apparatus as claimed in claim 4, wherein said relay means comprises a first relay operable in response to said third electrical signal, and a second relay responsive to the operation of said first relay for actuating said relay switches in said variable gain and zeroing means to connect different ones of said variable resistors of said variable gain and zeroing means into the amplifier means circuit.
Claim 9
Independent Claim
137 words
A method for automatically measuring a plurality of ranges of differential pressure of a fluid flowing across a pressure head producing device within a pipeline, comprising measuring the differential pressure across the pressure head producing device, generating a first electrical signal representative of said measured differential pressure within a first measurement range, detecting changes in the signal level of said first electrical signal, generating a second electrical signal the level of which is indicative of whether the level of said first electrical signal is above or below a predetermined signal level representative of one limit of said measurement range, generating a third electrical signal representative of a change in level of said second electrical signal, and changing the gain and electrical zero of an amplifier generating said first electrical signal in response to said third electrical signal.
Claim 10
Independent Claim
137 words
A method for automatically measuring a plurality of ranges of differential pressure of a fluid flowing across a pressure head producing device within a pipeline, comprising measuring the differential pressure across the pressure head producing device, generating a first electrical signal representative of said measured differential pressure within a first measurement range, detecting changes in the signal level of said first electrical signal, generating a second electrical signal the level of which is indicative of whether the level of said first electrical signal is above or below a predetermined signal level representative of one limit of said measurement range, generating a third electrical signal representative of a change in level of said second electrical signal, and changing the gain and electrical zero of an amplifier generating said first electrical signal in response to said third electrical signal.
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |