ELECTRODELESS CONDUCTIVITY MEASURING SYSTEM

• US 3,806,798 A
• Filed: 01/29/1973
• Issued: 04/23/1974
• Est. Priority Date: 01/29/1973
• Status: Expired due to Term

• Current Assignee: T. A. O. Gross
• Original Assignee: T. A. O. Gross
• Inventors: Gross, T. A. O.
• Primary Examiner(s): Lynch, Michael J.
• Application Number:
  US05/327,587
• Time in Patent Office: 449 Days
• Field of Search: 324/3R,3A,127 336/181
• US Class Current: 324/445
• CPC Class Codes: G01N 27/023 where the material is placed in the field of a coil
• CPC Class Codes: G01R 27/22 Measuring resistance of fluids

Abstract

An electrodeless system for measuring conductivity in fluids, incorporating a pair of toroidal ferromagnetic cores to be immersed in a fluid and disposed in essentially contiguous relationship, in which the winding on one core is excited by an oscillator at a constant frequency somewhat above the audio range, and in which the windings on both cores are so arranged that there is neither electromagnetic nor electrostatic unbalance from turn to turn of the assembled windings, so that the only coupling between the transmitter and receiver coils is effected by the fluid loop which links the cores.

Claims

1. An electrodeless conductivity measuring probe, comprising first and second toroidal ferromagnetic cores, means mounting said cores in adjacent coaxial relationship, and windings on said cores, each winding on each core comprising a plurality of turns, extending from a first terminal adjacent a first point on the core about and around the core in continuous series aiding relationship back and forth between said first point and a second point adjacent said first point and terminating at a terminal adjacent said first terminal, each of said turns being adjacent a turn of equal and opposite polarity in the presence of a current flowing in a predetermined sense through said winding.

2. An electrodeless conductivity measuring probe, comprising first and second toroidal ferromagnetic cores, means mounting said cores in adjacent relationship, a primary winding on said first core, a secondary winding on said second core, each of said windings extending in a series of at least one pair of courses from an input terminal, in a course wound about its associated core in a predetermined sense from a starting point, around the core, to a termination point adjacent said starting point and returning in turns in the same sense, in a course extending from said termination point to said starting point.

3. The apparatus of claim 1, further comprising an oscillator connected to a first of said windings on a first of said cores to apply an alternating voltage at a predetermined frequency to said first winding, and means connected to the second of said windings on the other of said cores to detect the voltage induced in said second windings by a conductive medium linking said cores.

4. The apparatus of claim 2, further comprising means for applying a voltage at a predetermined frequency across said primary winding, and means connected to said secondary winding for detecting a voltage induced across said secondary winding by a conductive medium linking said cores.

5. Apparatus for measuring the conductivity of a fluid, comprising first and second toroidal ferromagnetic cores, a primary winding on said first core comprising at least a first course of turns extending around said first core from a starting point to a termination point adjacent said starting point and returning from said termination point to said starting point around said first core in a second course for each first course in turns each mating with a corresponding turn of said first course, and a secondary winding on said second core comprising at least a first course of turns extending around said second core from a second starting point to a second termination point adjacent said second starting point and returning from said second termination point to said second starting point around said second core in a second course for each first course in turns each mating with a corresponding turn of said first course on said second core.

6. The apparatus of claim 5, further comprising means for exciting said primary winding with a constant voltage at a predetermined frequency, and means connected to said secondary winding for producing a signal in accordance with the voltage induced across said secondary winding.

7. The apparatus of claim 6, further comprising means for mounting said cores in closely spaced adjacent coaxial relationship.

8. The apparatus of claim 6, further comprising a fluid medium linking said cores.

9. The apparatus of claim 7, further comprising a fluid medium linking said cores.

10. Apparatus for controlling the flow of a fluid in dependence on the conductivity of the fluid, comprising a first toroidal ferromagnetic core, a second toroidal ferromaGnetic core, means mounting said core in mutually linked relationship by said fluid, a primary winding on said first core having adjacent turns each of equal and opposite polarity when a voltage is applied across said primary winding, said primary winding extending from a first terminal adjacent a first point on said first core about and around said first core in continuous series aiding relationship back and forth between said first point and a second point adjacent said first point and terminating in a second terminal adjacent said first terminal, a secondary winding on said second core having adjacent turns each of equal and opposite polarity when a voltage is induced across said secondary winding, said secondary winding extending from a third terminal adjacent a third point on said second core about and around said core in continuous series aiding relationship back and forth between said third point and a fourth point adjacent said third point and terminating in a fourth terminal adjacent said third terminal, means for inducing an alternating voltage across said primary winding, means for detecting the voltage induced across said secondary winding, and flow control means for adjusting the rate of flow of said fluid in a predetermined path in dependence on the voltage detected by said detecting means.

11. The apparatus of claim 10, in which said cores are immersed in said fluid.

12. The apparatus of claim 11, in which said mounting means mounts said cores in closely spaced adjacent coaxial relationship.

13. The apparatus of claim 10, in which said path comprises a conduit including a parallel path forming a fluid loop, and in which said mounting means mounts said cores in adjacent coaxial relationship above one leg of said loop.

14. Means for measuring the conductivity of a fluid, comprising first and second toroidal cores adapted to be linked by the fluid, a first winding on said first core comprising a first course of turns extending about and around said first core from a first starting point to a first termination point and returning from said first termination point to said first starting point in a second course of turns each mated with a turn of said first course so that essentially no external electromagnetic field is produced when a voltage is applied to said first winding, and a second winding on said second core comprising a first course of turns extending about and around said second core from a second starting point to a second termination point and returning from said second termination point to said second starting point in a second course of turns each mated with a turn of said first course on said second core so that essentially no external electrostatic field is produced by said second winding when flux is induced in said second core.

15. The apparatus of claim 14, further comprising means for applying an alternating voltage at a predetermined frequency to said first winding, and means connected to said second winding for producing an output signal in accordance with the voltage induced across said second winding.

16. The apparatus of claim 15, in which said cores are mounted in closely spaced coaxial relationship.

17. The apparatus of claim 16, in which said first termination point is adjacent said first starting point, and in which said second termination point is adjacent said second starting point.