Abstract: A method is disclosed for determining the presence of response abnormalities in magnetic sensors. The method includes placing the sensor in an applied magnetic field and collecting sensor resistance information as the magnitude and direction of the applied field is altered. The resistance values are then examined to determine the presence of response abnormalities.

Abstract: A method and system for the rapid automatic screening of GMR heads for Barkhausen noise during production. This system rapidly and repeatedly measures associated noise in a GMR head subjected to a smoothly-varying external transverse magnetic field. The repeated Transverse Magnetic-field Excited Noise (TMEN) measurements are automatically sorted into bins to form a histogram, which is then automatically evaluated to develop TMEN range and weighted sum measures, which are then compared with predetermined standards for automatic acceptance or rejection of the GMR head under test. The GMR sensor Barkhausen noise is quantified through the use of a bandpass filter to remove all direct sensor responses, leaving only the noise signals, which are then repeatedly sampled to develop valid statistical Barkhausen noise measures suitable for automated analysis.