Accession Number : ADA112042

Title :   Novel Eddycurrent Probe Development.

Descriptive Note : Final rept. 15 Jul 80-15 Aug 81,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Bahr,Alfred J ; Watjen,John P

PDF Url : ADA112042

Report Date : Dec 1981

Pagination or Media Count : 95

Abstract : This report describes the development of two novel eddy-current probes that are fabricated using printed-circuit techniques. The objective of this work was to develop reproducible, sensitive probes. One of the probes developed is a quarter-wave microstrip resonator that operates at 1 GHz, while the other probe used a broadband printed-circuit coil that can be operated in a frequency range of 10 to 400 MHz. The microwave probe was found to be very sensitive to open flaws, and seems well suited for detecting such flaws in parts that can be mechanically scanned past a fixed probe. The sensitivity of the printed-coil probe to open flaws was less than that of the microwave probe, but it was usually better than that exhibited by conventional coil probes. Also, it is easy to fabricate, is reproducible, and is moderately maneuverable. This report also presents data obtained using a modified floppy-disk head as an eddy-current probe at 100 kHz. This probe showed a high sensitivity to both open and closed flaws and is recommended for further evaluation and development.

Descriptors :   *Eddy currents, *Probes, *Test methods, *Nondestructive testing, Microwaves, Coils, Printed circuits, Defects(Materials), High sensitivity, Frequency bands, Cracks, Detection, Surfaces, Fabrication, Resonators, Broadband, Resonators

Subject Categories : Test Facilities, Equipment and Methods
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE