Car Wash Proximity Sensors

Photoelectric sensors consist of a transmitter unit which emits a modulated infrared light beam to a receiver unit, which receives the signal and then processes the signal to a PLC, relay or controller unit. There are three basic types of photoelectric sensing (detection principles):

• Thru-Beam: a transmitter emits a beam of light to receiver positioned opposite of each other.
• Diffuse Reflective/Proximity: a transmitter emits a beam of light towards a target object and the light is reflected back to the received, mounted adjacent to the transmitter.
• Retro-Reflective: transmitter emits a light beam towards a retro-reflector, positioned opposite, which reflects beam back to the receiver mounted adjacent to the transmitter. There is also a polarized retro-reflective version, which uses red light and polarisation filters. Filters polarise and filter the light transmitted and received by a retro-reflector, in order to avoid shiny or reflective objects not being detected and falsely sensed as the target retro-reflector.