Through-beam sensors emit light through the slots which are etched onto a coated glass disc. Pulses are generated as the beams are broken.
- Photoelectric encoders are very precise.
- Photoelectric encoders are very complex units consisting of many individual components.
- The production of coated glass discs is difficult and expensive. As compared to encoders with magnetic technology, they easily break when they are exposed to shock and vibration.
Incremental shaft encoders using magnetic technology generate pulses by rotating a magnet over a sensing chip and measuring the change in the field (Hall effect).
- Magnetic encoders are very robust and can withstand more shock and vibration than photoelectric encoders.
- The simple and compact design of magnetic encoders allows them to be packaged in smaller housings than photoelectric encoders.
- Standard magnetic encoders are less accurate and have slower response times than photoelectric encoders.
Encoders with solid shaft are attached to rotating machine shafts with the same or similar diameter using a coupling.
- Common solid shaft diameters are 6 mm and 10 mm.
- Different types of coupling and measuring wheels are available.
Solid shaft encoders are installed directly on the rotating shafts. Couplings are not needed. A hollow shaft encoder uses a flexible mounting flange, called a stator coupling.
Blind hollow shaft (open to one side):
- Encoders with hollow shaft open to one side are much more common than continuous hollow shaft encoders.
- Common diameters for blind hollow shafts are 6 mm or 10 mm.
Overview of available flange versions