[. . . ] www. vaisala. com IRU-9429 Snow Depth Sensor Features/Benefits Range from 150 mm to 10. 67 m (0. 5 to 35 ft) Easy to install Works on solids and liquids Easily configured for snow depth measurements Internal temperature compensation Virtually maintenance free Self-Contained Ultrasonic Sensor The IRU-9429 sensor uses ultrasonic technology to provide a non-contact method of detecting snow depth and presence/absence. [. . . ] The sensor records the time required for the sound wave to travel to the target and return. Using the speed of sound, which is a well-known variable, the sensor calculates the distance to the object. Until recently, the many factors that influence the speed of sound created inaccurate readings. Now with microprocessor technology, many of these variables can be factored into the equation and eliminated. The IRU-9429 sensor uses internal temperature compensation to offset the effects of these changes. Technical data General Operating Range Total Current Draw Transducer Type Sample Rate Resolution Accuracy Operating Temperature Beam Pattern Frequency 0. 15 to 10. 67 m (0. 5 to 35 ft. ) 75 mA @ 12 VDC Electrostatic Programmable (1-22 Hz) 2. 5 mm (0. 1 in. ) ± 0. 25% of detected range (with no temperature gradient) -40 to 60°C (-40 to +140°F) 9° off axis (at full signal strength and sensitivity settings) 50 kHz For more information, visit www. vaisala. com or contact us at sales@vaisala. com Ref. 2010-11-11 ©Vaisala 2010 This material is subject to copyright protection, with all copyrights retained by Vaisala and its individual partners. Any logos and/or product names are trademarks of Vaisala or its individual partners. [. . . ] All specifications -- technical included -- are subject to change without notice. [. . . ]