Accession Number : AD0275012

Title :   INVESTIGATION OF HALL EFFECT DEVICES FOR FLAW DETECTION IN METALS

Corporate Author : FRANKFORD ARSENAL PHILADELPHIA PA PITMAN-DUNN RESEARCH LABS

Personal Author(s) : ROSSNICK,J. ; SIPLER,H.

Report Date : MAR 1962

Pagination or Media Count : 1

Abstract : Hall generator instrumentation and special test fixtures were employed for the detection of flaws and measurement of flaw depth in ferrous and nonferrous metals. Magnetic leakage field distribution was measured in tubular steel specimens containing artificial surface flaws from 0.004 to 0.126 in. in depth. Field distribution was measured with respect to vertical and horizontal components of both field intensity and field gradient. Under the given test conditions, it was possible to estimate flaw depth from 0.017 to 0.126 in. with an accuracy of + or - 5%. With improved control conditions, even better accuracy may be possible. Other experimental results using the Hall Generator test technique for detecting magnetic field distortions associated with localized electric current-flow through cracked areas showed the feasibility of locating cracks in ferrous and nonferrous metals. Lack of adequate test specimens prevented an exact quantitative evaluation, but limited tests indicated the possibility of using the direct contact current-flow method for determing flaw depth in both ferrous and nonferrous metals. (Author)

Descriptors :   *HALL EFFECT, *MAGNETOMETERS, *NONDESTRUCTIVE TESTING, ALLOYS, ELECTRIC FIELDS, FRACTURE (MECHANICS), INTENSITY, MAGNETIC FIELDS, MEASUREMENT, METALS, QUALITY CONTROL, TEST EQUIPMENT, TEST METHODS

Distribution Statement : APPROVED FOR PUBLIC RELEASE