US3733897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensor assembly for vortex-type flowmeters
Assignee: Fischer and Porter Co
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Filing: 1971-10-14
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Granted: 1973-05-22
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Expires: 1991-10-14
Abstract
Abstract A sensor assembly for swirl, vortex and other types of hydrodynamic metering devices in which fluidic variations are sensed to afford an indication of flow rate or other fluidic values. The assembly is constituted by a heated transistor chip which is exposed to the fluid being sensed and is cooled thereby, the transistor being connected to an external circuit to define a direct-current amplifier whose base current is substantially constant, but whose collector current varies as a function of the heat extracted from the transistor by the fluid, thereby producing a corresponding output signal.
Inventors
- 👤 P Herzl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:27
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/05; G01F1/20; G01F1/32; G01F1/3236; G01P; G01P5/00; G01P5/10; G01P5/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
172 words
In combination with a vortex-type meter having a flow conduit in which a fluid to be measured is caused to produce fluidic variations at a frequency which is a function of flow rate; a sensor assembly for detecting said fluidic variations to produce an electrical signal at the same frequency, said assembly comprising: A. a transistor mounted in said conduit and exposed to said fluidic variations, said transistor having base, collector and emitter electrodes, said transistor having a small thermal mass and a large amount of surface area in relation to its mass whereby said transistor has a fast response time, B. an external electronic circuit connected to the electrodes of said transistor to define therewith a D-C amplifier maintaining said transistor in a heated condition, said transistor being cooled by said fluidic variations, the base current of said amplifier being substantially constant and the collector current thereof varying as a function of the heat extracted from said transistor, and C. means coupled to said collector to derive an output signal therefrom.
Claim 2
Dependent Claim
172 words
In combination with a vortex-type meter having a flow conduit in which a fluid to be measured is caused to produce fluidic variations at a frequency which is a function of flow rate; a sensor assembly for detecting said fluidic variations to produce an electrical signal at the same frequency, said assembly comprising: A. a transistor mounted in said conduit and exposed to said fluidic variations, said transistor having base, collector and emitter electrodes, said transistor having a small thermal mass and a large amount of surface area in relation to its mass whereby said transistor has a fast response time, B. an external electronic circuit connected to the electrodes of said transistor to define therewith a D-C amplifier maintaining said transistor in a heated condition, said transistor being cooled by said fluidic variations, the base current of said amplifier being substantially constant and the collector current thereof varying as a function of the heat extracted from said transistor, and C. means coupled to said collector to derive an output signal therefrom.
Claim 3
Dependent Claim
21 words
An assembly as set forth in claim 1, wherein said vortex meter is of the swirl type and includes swirl blades.
Claim 4
Dependent Claim
17 words
An assembly as set forth in claim 1, wherein said vortex meter is of the bluff-body type.
Claim 5
Dependent Claim
21 words
An assembly as set forth in claim 1, wherein saId transistor is sheathed in a protective layer having good thermal conductivity.
Claim 6
Dependent Claim
22 words
A sensor assembly as set forth in claim 1 further including a capacitor connected between the emitter and base of the transistor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |