Patent ID: 7227711

Claim:
A hard disk drive, comprising: an enclosure; a disk rotatably mounted to the enclosure and having a magnetic media; an actuator movably mounted to the enclosure and having a head for reading data from and writing data to the disk, the head also being a field sensor for detecting stray magnetic fields that are external to the hard disk drive; a controller for taking corrective actions to minimize a loss of data due to detection of a stray magnetic field with the head when a resistance of the head changes in a presence of the stray magnetic field, wherein the resistance of the head also is sensitive to temperature, such that a temperature inside the hard disk drive is measured so that a change in resistance of the head due to temperature change is normalized prior to taking corrective actions to minimize the loss of data; and a second head in the hard disk drive for reading data from and writing data to the disk, and for detecting the stray magnetic field, such that the head and the second head are monitored in conjunction with each other to cancel out a temperature sensitivity of the resistances of the heads.