Magnetic Field Sensors as Speed Monitors

Magnetic field sensors are generally based on the magneto-resistive or Hall-principle. Compared to optical speed sensors, resolvers and precision potentiometers, magnetic field sensors do not contain movable parts, such as shafts, bearings, code disks or slip rings. An aspect allowing them to be completely sealed making them tolerant to contamination of any type. Strong vibrations, which sometimes occur in rough applications, also do not affect magnetic field sensors. The variety of magnetic sensors is as extensive, as their versatility of practical applications: the gear wheel sensor with integrated preloaded magnet, the contact-less potentiometer, which generates its signals with an external bar magnet and the incremental speed sensors respectively distance measuring sensors which material measure consists of a magnetic ring or magnetic tape. The resolution thereby ranges from almost "rudimentary" at the gear-wheel sensor up to high resolution with the 12 bit single turn speed sensor with bus connection.