di-soric infrared distance detectors OAA... are characterised by a large operating distance, while having a very good colour independence.Thanks to the large diameter of light spot uneven surfaces of stones, sintered material or rough boards will be safely detected. Due to that di-soric infrared distance sensors OAA... are especially suitable for height control in concrete and gravel works, brickyards as well as professional saw mills. Two independently from each other adjustable thresholds enable diverse operation possibilities.