Apparatus and methods for three axis vector field sensor calibration

摘要

Provided are apparatus and methods for the calibration of a three axis vector field sensor that provides options for simpler and less expensive calibration of offset and gain for all three axes X,Y,Z. Sensor readings are taken from a number of orientations of the sensor obtained by rotating the sensor around a single axis 100 perpendicular to the calibration field g. By appropriately orienting the sensor relative to the calibration field, so that each axis forms a non-zero angle relative to the axis of rotation, and adopting a set of selected orientations in which successive orientations are obtained by rotating the sensor through 1.0472 radians around the axis of rotation 100, the effect of measurement noise on each measurement axis can be made to be approximately equal, and the effect can be maximized. The sensor readings taken during the calibration process are used to compute a gain and offset value for each axis of the three-axis vector field sensor. The three axis vector field sensor may be used in a mounting plate onto which a torsion balance (240, figure 3), capable of measuring partial pressure of oxygen, may be mounted. Also, the sensor may be used on a hard disc drive (300,310, figure 4) to sense shock such as dropping of the hard disc drive.