GB568701A - An improved electromagnetic apparatus for measuring and indicating small displacements - Google Patents

An improved electromagnetic apparatus for measuring and indicating small displacements

Info

Publication number
GB568701A
GB568701A GB891643A GB891643A GB568701A GB 568701 A GB568701 A GB 568701A GB 891643 A GB891643 A GB 891643A GB 891643 A GB891643 A GB 891643A GB 568701 A GB568701 A GB 568701A
Authority
GB
United Kingdom
Prior art keywords
coil
terminals
air gap
displacement
varied
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB891643A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BRITISH IRON AND STEEL CORP LT
Original Assignee
BRITISH IRON AND STEEL CORP LT
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BRITISH IRON AND STEEL CORP LT filed Critical BRITISH IRON AND STEEL CORP LT
Priority to GB891643A priority Critical patent/GB568701A/en
Publication of GB568701A publication Critical patent/GB568701A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
    • G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
    • G01D5/2013—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by a movable ferromagnetic element, e.g. a core

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Abstract

568,701. Magnetic measurements; inductance measurements ; determining dimensions of materials. BRITISH IRON & STEEL CORPORATION, Ltd., and DOUGLAS, A. June 3, 1943, No. 8916. 37] In apparatus for measuring small displacements an air gap in a magnetic circuit forming the core of a coil is physically varied in accordance with the displacement to be measured, and the coil is connected, in common, both across a 'source of constant frequency A.C. supply in series with a condenser and across an indicating instrument in series with another condenser, the arrangement being such that the instrument responds in accordance with variations in the air gap. The displacement to be measured is connected to a U-shaped iron yoke 1 forming part of the magnetic circuit of a T- shaped. iron member 2 having a coil 3 wound on its centre member. The magnetic circuit includes three equal air gaps 4 which are simultaneously varied by displacement of the yoke 1. One end of the coil 3 is connected to the junction of two equal variable condensers 5, 6, which may be mechanically coupled. The other end of the coil is earthed and connected to two terminals 8, 10. The other sides of the condensers 5, 6 are connected to terminals 7, 9. Across the condensers 5, 6 is connected a variable resistance 11 for balancing the resistance of the coil. A source of constant frequency oscillations is connected between the terminals 7, 8 and a detector is connected between the terminals 9, 10. When the air gap is normal the circuit 7, 5, 3, 8 is tuned to resonate at the frequency of the source and the circuit 9, 6, 3, 10 is similarly tuned, so that no voltage appears across the terminals 9, 10. If the air gap 4 is varied the inductance of the coil 3 is varied and the two circuits are no longer in resonance with the source, a voltage then appearing at the terminals 9, 10 of the indicating instrument. This voltage is a function of the displacement of the piece 1. If the variation of the air gap is kept within the limits of 1 per cent of the initial air gap, the relationship between the change in gap and change in inductance of the coil is substantially linear.
GB891643A 1943-06-03 1943-06-03 An improved electromagnetic apparatus for measuring and indicating small displacements Expired GB568701A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB891643A GB568701A (en) 1943-06-03 1943-06-03 An improved electromagnetic apparatus for measuring and indicating small displacements

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB891643A GB568701A (en) 1943-06-03 1943-06-03 An improved electromagnetic apparatus for measuring and indicating small displacements

Publications (1)

Publication Number Publication Date
GB568701A true GB568701A (en) 1945-04-17

Family

ID=9861792

Family Applications (1)

Application Number Title Priority Date Filing Date
GB891643A Expired GB568701A (en) 1943-06-03 1943-06-03 An improved electromagnetic apparatus for measuring and indicating small displacements

Country Status (1)

Country Link
GB (1) GB568701A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4526637A (en) * 1982-01-29 1985-07-02 The Goodyear Tire & Rubber Company Method of making conveyor belt

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4526637A (en) * 1982-01-29 1985-07-02 The Goodyear Tire & Rubber Company Method of making conveyor belt

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