Magnetdetektor

Magnetdetektor, or magnetic detector, is a device that senses magnetic fields or magnetic materials and converts the magnetic information into an electrical signal. These detectors span a broad range of technologies, from simple contactless sensors to highly sensitive instruments used in scientific research. The common goal is to translate magnetic interactions into a measurable electrical quantity such as voltage, current, resistance, or inductance.

Several core technologies are used in magnetdetektorer. Hall effect sensors measure the transverse voltage generated by a magnetic field in a thin conductor. Magnetoresistive sensors, including giant magnetoresistance (GMR) and tunnel magnetoresistance (TMR) devices, detect field changes via resistance variation. Fluxgate magnetometers use a ferromagnetic core driven into saturation to produce an output proportional to the external field. Superconducting quantum interference devices (SQUIDs) offer extreme sensitivity for very weak fields, at cryogenic temperatures. Inductive coils or magnetometers rely on changes in magnetic flux to produce signals and are common in metal detection and geophysical surveys.

Applications cover geophysics, space exploration, navigation and attitude sensing in aerospace, industrial automation, and non-destructive testing. In consumer electronics, compact Hall or magnetoresistive sensors enable position sensing and current measurement. In research contexts, magnetdetektorer are tailored for specific field ranges and noise environments, balancing sensitivity, bandwidth, temperature stability, and power consumption.

History traces magnet detection from early compass-based methods to modern solid-state and superconducting devices. Hall effect principles emerged in the late 19th century, while fluxgate sensors and SQUIDs were developed in the 20th century, driving advances across science and industry.