A diffuse reflection sensor is used for the direct detection of objects. The sensor transmits an ultrasonic pulse which is reflected by the target object and received and evaluated by the sensor. With this system the time of flight of the ultrasonic pulse from the sensor to the object and back again is evaluated. As opposed to photoelectric sensors colour, transparency or the object's surface shine do not play a role.
1x DC PNP 2x DC PNP 1x DC NPN 2x DC NPN analogue 4...20 mA analogue 0...10 V
300 mm 800 mm 1200 mm 1600 mm 2200 mm
For a retro-reflective sensor the ultrasonic pulse is reflected by a reflection surface, e.g. a wall or metal sheet and received by the sensor. The distance between sensor and reflection surface is continuously measured. If an object interrupts the distance between sensor and reflection surface, the switching output of the sensor switches. Retro-reflective sensors are always used when the object's alignment to the sensor can vary. Colour, transparency or the object's surface shine play no role.
1x DC PNP 1x DC NPN
1600 mm 2200 mm