US3745827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensation of a liquid flowmeter
Assignee: Smith Meter Inc
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Filing: 1971-02-16
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Granted: 1973-07-17
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Expires: 1991-02-16
Abstract
Abstract A petroleum product bulk plant line includes a flowmeter recorder which is temperature compensated by electrical control signals derived from a bridge circuit including a thermistor inserted within the flow line and a feedback potentiometer coupled to the compensated output. A differential amplifier and a reversible motor switching circuit is connected to the bridge circuit to selectively energize a motor and control an adjustable ratio drive assembly to provide a compensated output to the recorder. An electro-mechanical signal converter is coupled to the flowmeter and generates an electrical signal which is transmitted to a remotely located monitor having a drive assembly and a remotely located recorder. The thermistor within the flow line therefore provides a temperature responsive signal to the remotely located monitor to temperature compensate the drive assembly. The adjustable ratio drive assembly may include a nonlinear cam to compensate for changes in the liquid coefficient of expansion.
Inventors
- 👤 P Swanson
- 👤 C Tur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:10
CPC Classifications
G; G01; G01F; G01F15/00; G01F15/02; G01F15/06; G01F15/061; G01F15/063
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
219 words
An apparatus for providing temperature compensation in a system monitoring the volumetric liquid flow through a flow line, comprising a first output means including a local register and connected to said flow line for providing an output to drive said local register for providing a local gross registration proportional to the volumetric liquid flow, a sensing means including a thermistor having an impedance varying approximately linearly with sensed temperature connected to said flow line for providing an electrical signal proportional to the change in liquid temperature, a second output means electrically connected to said first output means and including a first remote register for providing a remote gross registration proportional to said local gross registration and a second register including an adjustable drive assembly, a compensating means including a motor, a variable element actuated by said motor and connected to control said adjustable drive assembly, and a control circuit including a differential amplifier and a switching circuit connected to said sensing means for providing an electrical signal proportional to the change in temperature of said liquid and electrically connected to said motor of said compensating means through said differential amplifier and switching circuit for selectively energizing said motor in accordance with changes in the temperature of the liquid to provide a temperature compensated recording at said second remote register.
Claim 2
Independent Claim
219 words
An apparatus for providing temperature compensation in a system monitoring the volumetric liquid flow through a flow line, comprising a first output means including a local register and connected to said flow line for providing an output to drive said local register for providing a local gross registration proportional to the volumetric liquid flow, a sensing means including a thermistor having an impedance varying approximately linearly with sensed temperature connected to said flow line for providing an electrical signal proportional to the change in liquid temperature, a second output means electrically connected to said first output means and including a first remote register for providing a remote gross registration proportional to said local gross registration and a second register including an adjustable drive assembly, a compensating means including a motor, a variable element actuated by said motor and connected to control said adjustable drive assembly, and a control circuit including a differential amplifier and a switching circuit connected to said sensing means for providing an electrical signal proportional to the change in temperature of said liquid and electrically connected to said motor of said compensating means through said differential amplifier and switching circuit for selectively energizing said motor in accordance with changes in the temperature of the liquid to provide a temperature compensated recording at said second remote register.
Claim 3
Dependent Claim
37 words
The apparatus of claim 1, wherein said control circuit includes means for providing a resistive impedance varying in response to energization of said motor, and said thermistor provides a resistive impedance varying in response to liquid temperature.
Claim 4
Dependent Claim
63 words
The apparatus of claim 2, wherein said control circuit means includes a pair of resistive impedance elements connected in bridge circuit configuration with said motor actuated impedance means and said sensing means, said bridge circuit having a constant input signal and providing an output signal varying in accordance to the difference in impedance betw between motor actuated impedance means and said sensing means.
Claim 5
Dependent Claim
40 words
The apparatus of claim 3, wherein said differential amplifier is connected to receive said output signal from said bridge circuit for providing an amplified signal proportional to said output signal to said switching circuit for selectively energizing said motor means.
Claim 6
Independent Claim
158 words
An apparatus to adjust a variable element connected to control an adjustable drive assembly of a temperature compensated meter responsive to the volumetric liquid flow through a flow line, comprising a compensating means connected to said meter and including a motor meanS to position said element for modifying the response of said meter, and a control circuit means including a sensing means connected to said flow line for providing an electrical signal proportional to the change in temperature of said liquid and a switching circuit electrically connected to said sensing means and having a pair of parallel connected transistors each having a base circuit mutually connected to a common input terminal and an emitter circuit connected to a common output terminal, said base circuits each containing a diode and said emitter circuits each containing a limit switch selectively actuated by said motor means for selectively energizing said motor means in accordance with changes in temperature of the liquid.
Claim 7
Independent Claim
158 words
An apparatus to adjust a variable element connected to control an adjustable drive assembly of a temperature compensated meter responsive to the volumetric liquid flow through a flow line, comprising a compensating means connected to said meter and including a motor meanS to position said element for modifying the response of said meter, and a control circuit means including a sensing means connected to said flow line for providing an electrical signal proportional to the change in temperature of said liquid and a switching circuit electrically connected to said sensing means and having a pair of parallel connected transistors each having a base circuit mutually connected to a common input terminal and an emitter circuit connected to a common output terminal, said base circuits each containing a diode and said emitter circuits each containing a limit switch selectively actuated by said motor means for selectively energizing said motor means in accordance with changes in temperature of the liquid.
Claim 8
Dependent Claim
68 words
The apparatus of claim 1, wherein caid compensating means further includes a cam rotatably connected to said motor, a cam follower engaging said cam and connected to position said variable element according to changes in sensed liquid temperature, said cam having a varying radius engaging said cam follower to position said variable element according to the varying coefficient of expansion of the liquid according to the temperature change.
Claim 9
Dependent Claim
145 words
A circuit to selectively energize a reversible motor for controlling the position of a variable element connected to control a temperature compensated meter responsive to the volumetric liquid flow through a flow line, comprising a bridge circuit means having an output circuit and including a temperature responsive element connected to said flow line and a position sensitive element connected to said motor to sense the motor output for providing a signal proportional to changes in liquid temperature, and a switching circuit means including a pair of parallel connected transistors electrically connected to said output circuit for selectively energizing said reversible motor in accordance with the magnitude and polarity of the signal proportional to changes in liquid temperature, and further including a disconnect means connected to sense the maximum operating limits of said variable element for de-energizing said reversible motor to prevent damage to said meter.
Claim 10
Dependent Claim
145 words
A circuit to selectively energize a reversible motor for controlling the position of a variable element connected to control a temperature compensated meter responsive to the volumetric liquid flow through a flow line, comprising a bridge circuit means having an output circuit and including a temperature responsive element connected to said flow line and a position sensitive element connected to said motor to sense the motor output for providing a signal proportional to changes in liquid temperature, and a switching circuit means including a pair of parallel connected transistors electrically connected to said output circuit for selectively energizing said reversible motor in accordance with the magnitude and polarity of the signal proportional to changes in liquid temperature, and further including a disconnect means connected to sense the maximum operating limits of said variable element for de-energizing said reversible motor to prevent damage to said meter.
Claim 11
Dependent Claim
23 words
The apparatus of claim 5 wherein said pair of diodes establishes a minimum liquid temperature differential to which said motor means will respond.
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) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |