GB460991A - Improvements in or relating to electromagnetic gauging and testing of materials - Google Patents

Improvements in or relating to electromagnetic gauging and testing of materials

Info

Publication number
GB460991A
GB460991A GB13185/35A GB1318535A GB460991A GB 460991 A GB460991 A GB 460991A GB 13185/35 A GB13185/35 A GB 13185/35A GB 1318535 A GB1318535 A GB 1318535A GB 460991 A GB460991 A GB 460991A
Authority
GB
United Kingdom
Prior art keywords
legs
core
magnetic
increase
instrument
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
GB13185/35A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of GB460991A publication Critical patent/GB460991A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
    • G01B7/06—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness
    • G01B7/10—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness using magnetic means, e.g. by measuring change of reluctance
    • G01B7/105—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness using magnetic means, e.g. by measuring change of reluctance for measuring thickness of coating

Landscapes

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

Abstract

460,991. Magnetic tests and measurements. KNIGHT, O. May 3, 1935, No. 13185. Void. Convention date, May 3,1934. [Class 37] An electromagnetic gauging or testing apparatus is provided with three or more legs, at least two of which are of magnetic material and magnetically linked. A three - legged electromagnet core M is placed on a surface X consisting of a thin coating of non-magnetic metal on a relatively thick body of magnetic metal O, it being required to measure the thickness of the coating X by the increase in the reluctance of the magnetic circuit comprising the core M and the body O. The core M is excited by means of a coil L 1 fed from a transformer T. On one of the legs is wound a secondary coil L2 in series with a copper oxide or other rectifier R and a direct-current measuring-instrument A. The rectified induced current may be opposed by an electromotive force tapped from a potentiometer resistance P3 fed from a battery B. The core M is moved over the surface to be tested, any variation in the thickness of the layer X causing a change in the voltage induced in the coil L2, which is indicated on the instrument A. A reversing switch S may be provided so that increase in the reading of the instrument A may correspond either to an increase or a decrease of the thickness of the layer X. One of the three legs of the magnet M need not form part of the magnetic system. The pole faces may be rounded and electroplated or otherwise coated with non-magnetic material. For measuring variations of a surface from a plane the magnet core M is provided with four or more legs, the contact faces of which are accurately lined up in a true plane. Departure of a surface from a true plane is indicated by increase of reluctance due to all four legs not being in contact with the surface.
GB13185/35A 1934-05-03 1935-05-03 Improvements in or relating to electromagnetic gauging and testing of materials Expired GB460991A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US460991XA 1934-05-03 1934-05-03

Publications (1)

Publication Number Publication Date
GB460991A true GB460991A (en) 1937-02-08

Family

ID=21941602

Family Applications (1)

Application Number Title Priority Date Filing Date
GB13185/35A Expired GB460991A (en) 1934-05-03 1935-05-03 Improvements in or relating to electromagnetic gauging and testing of materials

Country Status (1)

Country Link
GB (1) GB460991A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2563254A (en) * 1948-05-10 1951-08-07 Hydril Corp Thickness indicator
US2570633A (en) * 1948-04-01 1951-10-09 Rca Corp Intermediate frequency transformer
DE973803C (en) * 1941-09-30 1960-06-09 Siemens Ag Device for the direct determination of the loss figures of undivided electrical steel sheets, especially at 10 K Gauss and 15 K Gauss
EP0091429A1 (en) * 1981-10-14 1983-10-19 Combustion Eng Clad thickness measuring device.
US5311126A (en) * 1992-09-11 1994-05-10 The United States Of America As Represented By The Secretary Of The Navy Magnetic field strength threshold indicator for use in a magnetic particle inspection device
CN113219385A (en) * 2021-04-28 2021-08-06 纵目科技（上海）股份有限公司 Magnetic permeability test structure and test method

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE973803C (en) * 1941-09-30 1960-06-09 Siemens Ag Device for the direct determination of the loss figures of undivided electrical steel sheets, especially at 10 K Gauss and 15 K Gauss
US2570633A (en) * 1948-04-01 1951-10-09 Rca Corp Intermediate frequency transformer
US2563254A (en) * 1948-05-10 1951-08-07 Hydril Corp Thickness indicator
EP0091429A1 (en) * 1981-10-14 1983-10-19 Combustion Eng Clad thickness measuring device.
EP0091429A4 (en) * 1981-10-14 1984-05-17 Combustion Eng Clad thickness measuring device.
US4507609A (en) * 1981-10-14 1985-03-26 Combustion Engineering, Inc. Apparatus for nondestructively measuring the thickness of a magnetic flux conductive clad material over a magnetic flux conductive base material of a different permeability
US5311126A (en) * 1992-09-11 1994-05-10 The United States Of America As Represented By The Secretary Of The Navy Magnetic field strength threshold indicator for use in a magnetic particle inspection device
CN113219385A (en) * 2021-04-28 2021-08-06 纵目科技（上海）股份有限公司 Magnetic permeability test structure and test method

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