Variable reluctance linear position sensors and switches are non-contact devices. Variable reluctance sensing incorporates a "spring" of elastic, highly magnetically permeable material surrounded by two coils. Variable reluctance linear position sensors and switches use strain-based technology, wherein a magnetic circuit is formed, and the parameter input causes mechanical deflection of the spring member as a function of pressure, force, or acceleration. The deformation, strain, or displacement of the spring results in modulation of the inductance of the two coils, and this is read to indicate force, pressure, position, or other input to the sensor.

The most important specification for variable reluctance linear position sensors and switches is the operating distance to be measured. When thinking of this, care must be taken to include in the calculation the distance the target will be from the sensor, not just the displacement of the target. Also important are accuracy measured as a percentage of full scale, repeatability and minimum target diameter. Obviously, larger targets are easier to sense, but some variable reluctance position sensors and switches can detect targets that are quite small.

Variable reluctance linear position sensors and switches are non-contact devices. Variable reluctance sensing incorporates a "spring" of elastic, highly magnetically permeable material surrounded by two coils. Variable reluctance linear position sensors and switches use strain-based technology, wherein a magnetic circuit is formed, and the parameter input causes mechanical deflection of the spring member as a function of pressure, force, or acceleration. The deformation, strain, or displacement of the spring results in modulation of the inductance of the two coils, and this is read to indicate force, pressure, position, or other input to the sensor.

The most important specification for variable reluctance linear position sensors and switches is the operating distance to be measured. When thinking of this, care must be taken to include in the calculation the distance the target will be from the sensor, not just the displacement of the target. Also important are accuracy measured as a percentage of full scale, repeatability and minimum target diameter. Obviously, larger targets are easier to sense, but some variable reluctance position sensors and switches can detect targets that are quite small.

Variable reluctance linear position sensors and switches can output analog or digital signals, including computer signals. As features, variable reluctance position sensors can have EMI/RFI shielding, weld field immunity, short circuit protection and intrinsically safe ratings. They can detect both ferrous and non-ferrous targets, also magnetic and non-magnetic targets. They are available as a sensor or a sensor system, the latter incorporating controls and displays.