Linear magnetic sensing is becoming increasingly popular with the advent of low-cost Hall-effect sensors, which measure the vertical component of a magnetic field. These sensors can be used for a wide variety of applications, from monitoring of a valve position and volume controls in mixing consoles, to a slider in climate controls and collision detection in automatic cleaning robots.
Magnetic sensing is non-contact and non-invasive, which means that it can be more reliable in harsh environments where moisture or dirt can compromise resistive contact sensors. The technology is also much more cost effective than optical linear sensing alternatives.
Two techniques use a typical one-dimensional (1D) linear Hall-effect magnetic sensor to sense along a single axis to make linear measurements: the head-on and pass-by approaches. Both techniques use the Hall sensor with a magnet aligned with the axis.
