Patent ID: 6833706
Filing Date: 2004-12-21
Classification: G01V

Abstract:
An apparatus for measuring a radius of a hole, comprising:a support member having at least one non-articulated arm, each at least one arm having a first end and a second end, the first end rigidly attached to the support member; a magnet moveably attached to the support member via the second end of each at least one arm; a first magnetic sensor fixed to the support member for measuring a magnetic field of the magnet; a second magnetic sensor fixed to the support member for measuring a magnetic field of the magnet; and a third magnetic sensor fixed to the support, such that it is substantially unaffected by the magnetic field of the magnet in its direction of sensing, for measuring a magnetic field not produced by the magnet to distinguish the influence on the first or second sensor due solely to the magnetic field of the magnet.