Sensors
  Photoelectric Sensor Technology
    Light Source
      LED
      Incandescent
        Specular Reflective
    Beam Operation
      Through Beam
        Wave Guide
          Rigid Wave Guides
      Retro Reflective
        Fan Beam Scanner
      Proximity
        Convergent
  Conductive
  RF (electromagnetic)
  Impact
  Surge

Controllers
  Switching Controllers
    Output
      Electromechanical Relay
      Solid-State AC Switch
      Transistor Logic
        Open Collector
        Current Sink Or Source
    Control Function
      On Off
        Automatic On Off
      Latch
      Counter
        Batch Counter
        Toggle Batch Counter
      Shift Register
        Delay Line
        Externally Clocked Shift
      Time Delay
        Signal Loss Hold
        Energize Hold
          One Shot
          Delayed One Shot
          Repeat Cycle Timer
      Over Or Under Speed
  Analog

Configuration
  Self Contained
    Modular
  Wiring
    Two Wire Ac
      Compact Series Two Wire Ac
    Five Wire Relay
      Five Wire Ac Relay
      Five Wire Dc Relay
    Eight Wire Relay
    Three Wire Transistor Logic
  Remotely Operated
    Enclosure
      NEMA-1
      NEMA-12
  Potted
    Full Potted
    Potted Cable

Retro Reflective

A retro-reflective sensor generally provides a surer, simpler and more positive detection in applications where a reflector can be used.

Retro-reflective sensors project light through the control lens to a retro-reflective surface, which reflect the light directly back to the control lens.

This is similar to through-beam but an ordinary reflector is used instead of a separate sensor. Reflective discs are more efficient reflectors than retro-reflective tape. The reflective surface may be up to 15 degrees from perpendicular, and may even be vibrating.

The gain of the control is set so that the control will not respond to light reflected off of the object breaking the light beam. This is called proxing. If the object is shiny or glossy, it may be necessary to angle the light beam so that it does not strike the object at right angles. Polarizing the light beam may also help.

The beam-diameter is controlled by the diameter of the reflector and is not generally precise enough for detecting small objects.

Alternatives

• Through Beam
• Proximity
• Conductive

Products

Other Technology

Applications