Accession Number : ADD018231

Title :   Subsurface Examination of Non-Ferrous Material for Detecting Corrosion by Measuring Magnetic Traction.

Descriptive Note : Patent, Filed 24 May 95, patented 2 Jul 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Gammell, Paul M

Report Date : 02 Jul 1996

Pagination or Media Count : 5

Abstract : A magnetic field generator positioned externally of a nonferrous metallic structure being examined is rotated at a relatively low speed to produce a rotating magnetic field penetrating the metallic structure to a selected depth as a function of spacing between magnetic poles of the generator parallel to a planar surface of the metallic structure. Traction between the metallic structure and the magnetic field accompanying its rotation is measured. Corrosion of the metallic structure at subsurface depths is detected and quantified from such traction measurements.

Descriptors :   *MAGNETIC FIELDS, *DETECTION, *CORROSION, *TRACTION, *SUBSURFACE, METALS, MEASUREMENT, MATERIALS, DEPTH, LOW VELOCITY, PLANAR STRUCTURES, GENERATORS, ROTATION, POLARITY, PATENTS

Subject Categories : Inorganic Chemistry
      Properties of Metals and Alloys
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE