Diffuse sensors
The transmitter and receiver in diffuse sensors are arranged side-by-side in a component. In contrast to the retro-reflective sensor, a diffuse sensor does not have its own reflector. Instead it uses the reflective property of the object or workpiece that enters its transmission range. If the light hits a reflective body, it is redirected to the receiver and the sensor output is switched. This operational principle means diffuse sensors can only be used if the workpiece or machine part to be detected is highly reflective (e.g. metallic surfaces, light colours).