Accession Number : ADD016393

Title :   Magnetic Field Strength Threshold Indicator for Use in a Magnetic Particle Inspection Device.

Descriptive Note : Patent, Filed 11 Sep 92, patented 10 May 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Mittleman, John ; DeNale, Robert ; Brown, Lawrence M

Report Date : 10 May 1994

Pagination or Media Count : 6

Abstract : Field strength of an electromagnet is monitored at a threshold with a coupling coil positioned to monitor magnetic flux in a leg of an electromagnet. In the context of magnetic particle inspection for surface flaws (e.g. cracks) in ferromagnetic materials, sensing magnetic flux a portion of a magnetic circuit including the material being inspected provides a continuous direct indication of whether or not the magnetic field strength produced produced is sufficient for reliable inspection to be performed. Since the magnetic flux in the electromagnet will be reduced with increases in reluctance of the magnetic circuit, the continuous monitoring of magnetic field strength also effectively monitors correct inspection technique by the magnetic particle inspection methodology

Descriptors :   *FERROMAGNETIC MATERIALS, *MAGNETIC FIELDS, *MAGNETIC DETECTION, COILS, COUPLINGS, CRACKS, ELECTROMAGNETS, INSPECTION, MAGNETIC CIRCUITS, MONITORING, MONITORS, PARTICLES, SURFACE ANALYSIS, THRESHOLD EFFECTS, SURFACE ROUGHNESS, PATENTS

Subject Categories : Magnetic & Electric Fld Detection & Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE