Editing Magnetometer (section)

====Magnetoresistive devices====
{{Main|Magnetoresistance}}
These are made of thin strips of [[Permalloy]], a high [[magnetic permeability]], nickel-iron alloy, whose electrical resistance varies with a change in magnetic field. They have a well-defined axis of sensitivity, can be produced in 3-D versions and can be mass-produced as an integrated circuit. They have a response time of less than 1 microsecond and can be sampled in moving vehicles up to 1,000 times/second. They can be used in compasses that read within 1°, for which the underlying sensor must reliably resolve 0.1°.<ref>{{citation|title=Applications of Magnetoresistive Sensors in Navigation Systems|author=Michael J. Caruso|publisher=Honeywell Inc.|url=http://www.ssec.honeywell.com/position-sensors/datasheets/sae.pdf|archive-url=https://web.archive.org/web/20100705002122/http://www.ssec.honeywell.com/position-sensors/datasheets/sae.pdf|url-status=dead|archive-date=5 July 2010|access-date=21 October 2012}}</ref>