An ultrasonic sensor sends short sound pulses above the audible range and measures the time until the echo returns from the object. From the time of flight it calculates the distance, so it detects glass, liquids, granulate and shiny or black surfaces that confuse optical sensors, and it is not affected by dust, mist or colour. Typical uses are level in tanks and silos, distance and position measurement, roll diameter and object detection on conveyors. SCN supplies ultrasonic sensors from Wenglor and the UK1D\/G2 series.<\/p>\n
The range covers measuring ranges from a few millimetres in a fork sensor up to 6,000 mm, in compact cuboid, M18 and M30 housings. Many models have IO-Link together with 4\u201320 mA or 0\u201310 V analogue outputs or PNP\/NPN switching outputs, IP67 or IP68 protection and M12 connectors, and some have stainless steel 316 housings. For short distances and very fast detection, see photoelectric sensors<\/a>; all sensor types are under Sensors<\/a>.<\/p>\n How to choose:<\/strong> start with the distance to the object and the size and surface of the target, then the housing that fits your mounting. Choose an analogue output for continuous level or distance, a switching output for presence, and IO-Link if you want to set and monitor the sensor from the PLC.<\/p>\n An ultrasonic sensor works by echo. A piezo transducer sends a short sound pulse and then listens for the reflection from the object. The distance is half the time of flight multiplied by the speed of sound, about 343 m\/s in air at 20 \u00b0C. Because the speed of sound changes with air temperature, industrial sensors compensate for temperature to keep the reading accurate.<\/p><\/details>\nFrequently asked questions<\/h3>\n
How does an ultrasonic sensor work?<\/summary>