US3603873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conductivity sensor
Assignee: Halliburton Nus Corp
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Filing: 1970-01-14
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Granted: 1971-09-07
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Expires: 1990-01-14
Abstract
Abstract A conductivity sensor having a fluid immersible, conductivity transformer comprised of a pair of toroidal cores on each of which are wound two windings, one of the windings on one core being the input winding, one of the windings on the other core being the output winding, the second winding on the input core providing a reference voltage and the second winding on the output core providing a means for negative feedback to null the flux in the second core. The output voltage and the reference voltages are compared to produce a measurement which is a function of the conductivity of the medium in which the conductivity transformer is immersed.
Inventors
- 👤 Uldis Cirulis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:27
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/023
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
226 words
A conductivity sensor for measuring the conductivity of a fluid comprising: a first toroidal core and a second toroidal core placed in juxtaposition and immersed in the fluid; a first winding and a second winding wound on the first toroidal core; a third winding and a fourth winding wound on the second toroidal core; a source of alternating current connected to the first winding to thereby cause an alternating current to flow therein and to induce an alternating current in the second winding through inductive coupling in the first toroidal core and in the third winding through inductive coupling in the fluid; first conversion means whose input is connected to the second winding so as to produce a reference voltage at the output of the first conversion means; second conversion means whose input is connected to the third winding so as to produce an output voltage at the output of the second conversion means; the fourth winding being connected to the output of an amplifier whose input is connected to the third winding so as to produce a negative feedback flux which eliminates the effect of the changes in the characteristics of the second toroidal core on the output voltage; and comparison means for comparing the reference voltage and the output voltage to produce a signal which is a function of the conductivity of the fluid.
Claim 2
Dependent Claim
226 words
A conductivity sensor for measuring the conductivity of a fluid comprising: a first toroidal core and a second toroidal core placed in juxtaposition and immersed in the fluid; a first winding and a second winding wound on the first toroidal core; a third winding and a fourth winding wound on the second toroidal core; a source of alternating current connected to the first winding to thereby cause an alternating current to flow therein and to induce an alternating current in the second winding through inductive coupling in the first toroidal core and in the third winding through inductive coupling in the fluid; first conversion means whose input is connected to the second winding so as to produce a reference voltage at the output of the first conversion means; second conversion means whose input is connected to the third winding so as to produce an output voltage at the output of the second conversion means; the fourth winding being connected to the output of an amplifier whose input is connected to the third winding so as to produce a negative feedback flux which eliminates the effect of the changes in the characteristics of the second toroidal core on the output voltage; and comparison means for comparing the reference voltage and the output voltage to produce a signal which is a function of the conductivity of the fluid.
Claim 3
Dependent Claim
39 words
The invention of claim 1 including: a resistor; and wherein the amplifier is connected between the third winding and the second conversion means; the resistor being connected in series with the output of the amplifier and the fourth winding.
Claim 4
Dependent Claim
28 words
The invention of claim 2 wherein the comparison means is a voltage to frequency converter having a frequency output which is proportional To the conductivity of the fluid.
Claim 5
Dependent Claim
15 words
The invention of claim 2 wherein the first conversion means is an absolute value amplifier.
Claim 6
Dependent Claim
15 words
The invention of claim 2 wherein the second conversion means is an absolute value amplifier.
Claim 7
Dependent Claim
28 words
The invention of claim 2 wherein the comparison means is a null detecting, voltage divider having a voltage output which is proportional to the conductivity of the fluid.
Claim 8
Dependent Claim
15 words
The invention of claim 1 wherein the first conversion means is an absolute value amplifier.
Claim 9
Dependent Claim
15 words
The invention of claim 1 wherein the second conversion means is an absolute value amplifier.
Claim 10
Dependent Claim
28 words
The invention of claim 1 wherein the comparison means is a null detecting, voltage divider having a voltage output which is proportional to the conductivity of the fluid.
Claim 11
Dependent Claim
28 words
The invention of claim 1 wherein the comparison means is a voltage to frequency converter having a frequency output which is proportional to the conductivity of the fluid.
Claim 12
Dependent Claim
19 words
The invention of claim 10 wherein the first conversion means and the second conversion means are absolute value amplifiers.
Claim 13
Dependent Claim
19 words
The invention of claim 9 wherein the first conversion means and the second conversion means are absolute value amplifiers.
Claim 14
Dependent Claim
19 words
The invention of claim 3 wherein the first conversion means and the second conversion means are absolute value amplifiers.
Claim 15
Dependent Claim
19 words
The invention of claim 6 wherein the first conversion means and the second conversion means are absolute value amplifiers.
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) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |