AN INVESTIGATION OF VARIOUS PROCEDURES FOR ANALYSIS OF MICROMAGNETIC BARKHAUSEN SIGNALS FOR NONDESTRUCTIVE EVALUATION OF STEELS

Current research undertaken at Iowa State University has been concerned with both the theoretical and experimental aspects of the Barkhausen effect. Here we discuss mainly the experimental techniques and including new Barkhausen effect instrumentation to detect and measure the emissions from ferromagnetic materials under the action of an alternating magnetic field H [21]. The capability of the system includes measurements of RMS Barkhausen voltage signals induced in a flux coil, pulse height analysis of these signals, frequency spectrum analysis, and Barkhausen pulse count rate analysis.