Magnetic sensors - System description

  • Detection even through non-magnetisable metals
  • Small housings with very long sensing ranges up to 100 mm
  • Cylinder and rectangular designs for demanding applications
  • High mechanical stability in case of shock or vibration
  • Flush or non-flush installation in non-magnetisable metals

Magnetic sensors
Magnetic sensors are used for the detection of positions without contact or wear and tear in control technology. They come into their own where inductive sensors reach their limits.
Advantage: Magnetic sensors offer small designs with very long sensing ranges. Depending on the orientation of the magnetic field the sensor can be damped from the front or from the side.

Since magnetic fields penetrate all non-magnetisable materials, the sensors can detect magnets through walls made of non-ferrous metal, stainless steel, aluminium, plastic or wood.

In gate systems, for example, the magnet sensor only detects the magnet which is to be detected. Any possible influences by aluminium in the environment do not impact or reduce the sensing range.

In the food industry the magnetic sensor is often used in connection with pigs (cleaning devices which pass through the inside of pipes). By means of magnetic sensors their exact position can be detected from the outside through the wall of the stainless steel pipe.

Operating principle
Magnetic sensors from ifm electronic use GMR (Giant Magneto Resistive Effect) technology. The measuring cell consists of resistors with several extremely fine, ferromagnetic and non-magnetic layers. Whereas in a conventional Wheatstone bridge circuit two GMR resistors are used, a large signal proportional to the magnetic field is produced if a magnetic field is present. As from a defined threshold value an output signal is switched via a comparator.

More information

System overview — Magnetic sensorsProduct Innovations — Magnetic sensors

Magnetic switches and magnetic sensors | ifm
The sensor switches as soon as the magnet has reached the switch-on point. The direction of movement of the magnet is not important. This is the preferred arrangement.