Introduction Series SW-605:- The Optical Proximity Switches are a reliable solution for 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 and 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.

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 -

1) Component positioning sensing in Electronic Industry. 2) Counting of bottles, Jars, Containers etc. 3) Glass sheet position sensing. 4) For security & safety in Machine Tools, Presses etc. 5) Color sensing applications.

Principle Of Operation:-These switches incorporate an Infra-red transmitter & receiver device housed in a single 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 the object is sensed.

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

Diffuse SCan (DS):- type switches have both transmitter & receiver in the same enclosure. The closely focussed 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 greater sensing distance compared to DS type. The receiver does not consider any reflections from other objects or sources.

Explanation Of Technical Terms

Standard Object:- The sensing distance specified for DS switch is considered with a white object having minimum 90% reflectivity.

Sensing Distance:- This is the maximum specified range of a sensor measured at 25°C using a standard object.

Construction:-These switches are offered in tubular metallic, acrylic & plastic enclosures. Standard models are available with integrated 2-meter long cable. Switches with built-in (Male) connectors (International M8/M12 size) for quick connections are also available.

Switches with Optical Fibre:- Special model of Optical Switches are available with an integrated Optical Fibre cable for flexible mounting and for sensing miniature objects / high temperature objects. This switch is of through-beam type and is available in H type enclosures.