The Optical Proximity Switches are a reliable solution of automation where other Proximity Switches have limitations. These are infra-red type sensors incorporating advance and reliable technology.These switches have a distinct advantage of higher sensing distance over inductive & capacitive type of switches. These can work more reliably in a noisy electro-magnetic radiation environment. As an infra-red wavelength light source is used, it is immune to visible light interference.

Principle of operation

These switches incorporate an infra-red transmitter & receiver device housed in a signal enclosure or separate enclosures. The precision pulsed transmitter beam is interrupted or reflected by the object. The advanced electronic circuit generates an effective output signal when object is sensed.

Thru-Beam (TB) type switches have separate transmitter & receiver. The object is sensed when the beam is interrupted.

Diffuse Scan (DS) typoe switches have both transmitter & receiver in the same enclosure. The closely focused beam is reflected back by the object.

Retro-Reflective (RR) type switches use a special reflector to reflect back the beam. When an object interrupts the beam, an output signal is generated. These models have grater sensing distance compared to DS type. The receiver does not consider any reflections from other objects or sources.

Applications

These switches are very useful for counting and position sensing applications in Pharma, Food, Paper, Plastic & Automobile industry. They also work effectively in level sensing applications for solids, grains, sand, ice and other non-metallic bulk material.

Some typical applications are:•

• Component positioning sensing in electronic industry
• Counting of bottles, jars, containers etc.
• Glass sheet position sensing
• For security & safety in Machine Tools, Presses etc.
• Color sensing applications