Snow sensor SHM31

Overview
The SHM31 provides millimeter-accurate, non-contact snow depth measurements using a visible laser beam directed to the ground. Designed for fixed installation up to 16 m above snow-free ground, the sensor delivers reliable readings within seconds in a wide range of weather conditions. Integrated heating options protect the optical window and extend laser diode lifetime, while the robust IP68 housing minimizes maintenance.

Key features

• Visible measuring laser beam for non-contact snow depth measurement
• Millimeter accuracy with fast measurement cycle (seconds)
• Mounting height up to 16 m above snow-free ground
• Multiple heating functions for reliable operation in adverse weather and extended diode life
• Rugged IP68 housing designed for low maintenance (regular cleaning before season)
• Calibration verification possible using reference target plate
• Service typically limited to occasional laser diode replacement

Technical specifications

• Product Number: 8365.3
• Power supply: 12, 24 VDC
• Laser Class: Laser class 2 (IEC 60825-1:2014; complies with 21 CFR 1040.10 except for deviations per Laser Notice No. 50, 24 June 2007)
• Precision: 0.2 in (5 mm)
• Measurement Range (EU): 0 - 49 ft (0 - 15 m)
• Dimensions: 11.9 x 5.1 x 9.2 in (302 × 130 × 234 mm)
• Operating temperature range: -40 - +122 °F (-40 - +50 °C)
• Power consumption: without heater approx. 0.7 W (at 24 Vdc, 10 s interval); with window heating approx. 3.4 W; max 18 W
• Interface: RS-485, RS-232, SDI-12
• Accuracy: ± (5 mm + 0.06 %)
• Weight (EU): 5.2 lbs (2.3 kg)
• Casing rating: IP68
• Compliance: 2014/30/EU & RoHS 2011/65/EU, EN 61326-1:2012 (industrial)
• Protocol: RS485 - ASCII, UMB, Modbus; RS232 - ASCII, UMB; SDI-12 - SDI-12
• Measurement technology: laser distance measurement using phase comparison and time-of-flight
• Repeatability: 0.02 in (5 mm)
• Recommended mounting configurations: 0.3 - 52 ft (0.1 - 16 m)