Hall Effect against Shunt Sensing on the High Side
High-side shunts deliver superior low-current accuracy under high temperatures, while integrated Hall sensors reduce high-current thermal power loss.
Anisotropic Magnetoresistance
Magnetic Resistance
Electrical resistivity depends on the angle between the magnetization vector and the direction of the electric current flowing through a ferromagnetic conductor. Anisotropic magnetoresistance characterizes this change in resistance as the magnetic field alters the internal domain alignment of the material. This phenomenon provides a foundation for solid state sensors that detect local magnetic field gradients without mechanical movement.
Installation Tolerance
Precision in sensor alignment remains necessary because the output signal varies with the cosine square of the angle between current and magnetization. Mechanical mounting errors induce an offset that calibration routines must isolate from the actual field measurement. Thermal expansion of the supporting substrate also introduces a drift that changes the sensitivity coefficient over long duty cycles.
Sensor Calibration
Systematic testing verifies the sensitivity of a bridge circuit against a known reference field produced by a Helmholtz coil assembly. Voltage output scales linearly with the field magnitude once the device undergoes an initial bias adjustment to reach the center of its linear response range. Standard verification procedures involve sweeping the external field through a full rotation to map the characteristic curve and identify hysteresis effects that limit resolution.
Field Application
Industrial controllers utilize these sensors to monitor shaft rotation speeds or position in harsh environments where optical encoders fail due to dust or fluid contamination. High sensitivity to small field changes allows the detection of ferromagnetic objects moving past the sensing surface at high velocity. The device output maintains stable performance across wide temperature ranges when the application circuit includes compensation for the temperature coefficient of the sensor resistance.