FAQ03125 of Photoelectric Sensors FAQ

Role of Slit

The Slit is mounted on the emitter and receiver of Through-beam Photoelectric Sensors to decrease the lens diameter and narrow the light beam. This is done to increase the sensing performance for the smallest detectable object.

Usage

One set of two Slits for the emitter and receiver is generally used mounted to the emitter and receiver of a Through-beam Photoelectric Sensor. It is also possible, however, to use a Slit on only either the emitter or the receiver, depending on the sensing distance and the size of the sensing object.

Slits, however, cannot be used on Reflective Photoelectric Sensors (e.g., Retroreflective, Diffuse-reflective, Convergent-reflective, or Distance-settable Sensors).