Cylinder sensors - System description
- Self-clamping fixture for easy adjustment and quick mounting
- Convenient: can be easily inserted into the slot from the top
- Suitable for the most commonly used C- and T-slots
- Unit versions available with connection cable and M8 or M12 cable plug
- Wide selection of adapter accessories
Cylinder sensors are used for position detection of pistons in pneumatic cylinders. They are directly mounted onto the cylinder. The ring magnet attached to the piston is sensed through the housing wall of non-magnetisable material (e.g. aluminium, brass or stainless steel). ifm electronic offers a standard solution for different cylinder types and manufacturers.
Cylinder sensors of ifm electronic use state-of-the-art GMR and AMR technology.
A GMR element consists of resistors with several extremely thin ferromagnetic and non-magnetic layers. Whereas in a conventional Wheatstone bridge circuit two GMR resistors are used, a proportional signal is produced if a magnetic field is present. As from a defined threshold value an output signal is switched via a comparator.
An AMR element consists of thin ferromagnetic stripes. Electrical resistance is highest without external magnetic fields. The effect of a magnetic field reduces resistance. This change is converted into a switching signal by the internal electronics. Advantage: This method enables exact measurement of even very small changes of the magnetic field where space is extremely limited. This results in a smaller hysteresis and a short travel distance. So the sensors can be used wherever exact positioning is required (e.g. short-stroke cylinder).
Reed switches also detect a magnetic field and can be used as pulse pick-ups.