Glossary · Sensors and measurement
Hall-effect sensor
Also known as: Hall sensor
German: Hall-Sensor
In sensor technology, a Hall-effect sensor is a sensor that detects a magnetic field by the voltage that the field induces across a current-carrying semiconductor (the Hall effect). It is used as a switch or as a linear sensor for position, speed and current.
- Sensors
In one sentence
A Hall-effect sensor detects magnetic fields through the Hall effect and is used for position, speed and current measurement without contact.
Example
Hall-effect sensors in a brushless DC motor tell the drive the rotor position so that it can switch the windings at the right time.
How it applies
- Engineering: Hall switches detect a magnet, for example on a pneumatic cylinder piston; linear Hall sensors measure field strength for angle, position or current. They work without contact and are not affected by dirt, but external magnetic fields and temperature influence them.
- Commissioning: Magnet position, distance and pole orientation must match the design. A turned magnet can invert or cancel the signal.
- Maintenance: When replacing magnets or sensors, use the specified parts; a different magnet strength changes the switching point.
- Documentation: Describe the magnet and its orientation in assembly and spare-parts documentation, not only the sensor.
Hall-effect sensor vs. inductive sensor
A Hall-effect sensor reacts to a magnetic field, usually from a permanent magnet. An Inductive sensor generates its own alternating field and reacts to metal objects, without needing a magnet on the target.