With diffuse sensors, the target itself reflects the ultrasonic impulses. When the target enters a preset sensing area, the echo reflected from it causes the device to switch. To eliminate false switching, the Contrinex ultrasonic Diffuse family includes excellent background suppression in Miniature (M12) and Small (M18) devices. The latter are available in normal or short housings, including 90°sensing and teach-in versions. Sensing ranges extend from 30 to 700 mm.
Reflex sensors, a fixed reflector (e.g. a small metal plate) is mounted facing the device. The switching range is set to this reflector. If an object comes between the ultrasonic sensor and the reflector, the sensor no longer recognizes the latter, which causes the output to switch. The Contrinex ultrasonic Reflex family comprises Small (M18) devices with short housings, including 90° sensing and teach-in. Use of a reflector eliminates the blind zone, so that sensing ranges extend from 0 to 700 mm.