MAGNETIC FIELD SENSORS
Magnetic field sensors have a current flowing through them, and can detect magnetic fields of a certain strength. If a magnet (magnetic field) is brought to the sensor, it delivers an output voltage. For this purpose, a magnet is integrated into the piston; this magnet can then be detected from outside. This allows unproblematic flexible, individual adjustment of the sensing points. However, when magnetic field sensors are used the cylinder housing has to be non-magnetic so as not to influence the magnetic field being detected.
The operational limits of these simple position sensors are at 105 °C (221 °F). AHP Merkle also offers a solution that goes up to 130 °C (266 °F); this is implemented through the use of switches with displaced electronics. Here the evaluation electronics are not located directly on the sensor element, but rather at a distance of up to 0 .5 m (1 .64 ft) via a cable connection.