Patent ID: 7284337

Claim:
A probe head for a coordinate measuring machine, comprising: a housing, a stylus resiliently suspended in the housing, and a sensor arrangement for detecting deflections of the stylus relative to the housing, the sensor arrangement comprising a first Hall sensor having a first magnet and a first Hall element arranged in a vicinity of the first magnet and a second Hall sensor having a second magnet and a second Hall element arranged in a vicinity of the second magnet, with the first Hall sensor being designed for providing a first Hall voltage as a function of a deflection of the stylus in a direction perpendicular to the stylus, and with the second Hall sensor being designed for providing a second Hall voltage as a function of a deflection of the stylus in a direction parallel to the stylus, and wherein each of the first and second magnets has a North Pole and a South Pole, and wherein each of the first and second magnets is arranged for laterally passing by the respective first and second Hall elements in a direction from the North Pole to the South Pole or vice versa, when the stylus is deflected, such that a Hall voltage having a polarity change and a voltage range around the polarity change is generated by the Hall elements, wherein the sensor arrangement is adapted to process said voltage range for providing a continuous measure of the deflection of the stylus, and wherein the stylus is suspended for swiveling about a fulcrum defining a radial plane perpendicular to the stylus, wherein the first magnet has a first symmetry plane defined between its North Pole and its South Pole, and wherein the first magnet is located with the first symmetry plane lying in the radial plane, when the stylus is in rest position.