Serviceline Industrial Sensors
Serviceline Explosion Protection

Special Magnetic Field Sensors

Sensors optimized for use in special application areas can be found below. These are application-specific sensors.

Magnetic Field Sensor for Piston Position Query

The MB-F32-... series has been specially designed for querying the piston position in pneumatic and hydraulic systems.

The sensor offers a "magnetic insight function," which allows a piston to be detected through the wall of a hydraulic cylinder. For this purpose, the damping magnets are integrated into a magnetic system on the piston of the pneumatic or hydraulic system. As soon as the piston crosses the sensor, the sensor generates a switching signal. The sensor can therefore be used to determine the piston position and count the piston stroke.

How It Works

The MB-F32 sensor is sensitive to magnetic fields and requires a change in the magnetic field to change the switch state. The magnetic pole piece of the piston induces a partial magnetic field in the steel cylinder wall.

The sensor switches as soon as the partial magnetic field crosses it.

Figure: Sectional drawing of a cylindrical pneumatic system

The piston moves back and forth with the piston rod in the cylinder. A pole piece specially designed for this purpose is equipped with magnets arranged in an axial direction. These magnets magnetize parts of the steel cylinder wall. When the magnetic system passes the sensor, the sensor detects the position of the piston.

Installation Conditions for the "Magnetic Insight Sensor"

The MB-F32 magnetic field sensor is mounted on the outside of the steel cylinder wall and secured with a tension strap. To create a functioning system, a special pole piece must be attached to the piston inside the hydraulic cylinder. The shape and geometric dimensions of the pole piece, as well as the size and number of magnets, depend on the characteristics of the cylinder piston system. The specialists at Pepperl+Fuchs will be happy to help you plan the magnetic system.

Pepperl+Fuchs uses special software (MagCalc32) to determine the required magnetic system with regard to its mechanical design and the type and number of damping magnets. This results in customized solutions for the respective application.

The MB-F32-A2 series for querying piston positions in pneumatic and hydraulic systems has the following features:

  • Complementary output stages
  • Voltage drop at the switched contact
  • Unlimited number of switching cycles

The magnetic field sensor is available with a cable or plug connection.

Hall-Effect Sensor Systems for Safe Applications

40FY* or 50FY* with magnets for use with:

  • Safety logic amplifier ("logic controller") FYQLA1-140R-3
  • Safety monitor KE5D2-6H/2R-S

The magnetic-field safety sensors are used to protect people from injury. The sensors can be used for physical access control in hazardous areas and similar applications.

Magnetic Field Sensors

Take a look at the range of Pepperl+Fuchs magnetic field sensors.