Retro-reflective sensors sometimes referred to as reflex, retro and polarized retro-reflective, have the emitter and receiver housed in a single housing. A cube style reflector or certain reflective tapes are mounted opposite the sensor and the light beam, either infrared, red or laser is reflected back to the receiver. When an object breaks the beam, the output is activated.
These sensors, with ranges up to 20 meters, can detect objects regardless of color or surface texture. Highly reflective or shiny surfaces may require polarized retro-reflective sensors that have integrated polarizing filters to eliminate false triggers or second surface reflections. The maximum sensing distance of a photoelectric sensor is dependent on the size and efficiency of the reflector.
Applications:
- Parts counting
- Conveyors
- Clear glass detection
- Error proofing
- Gate control