OTT HydroMet - Model LUFFT SHM31 - Snow Depth Sensor
The laser-based snow depth sensor LUFFT SHM31 stands for millimeter-accurate snow level detection over long distances in all weather conditions without any maintenance, due to opto-electronic/laser based rangefinder technology.
Millimeter-accurate snow levels in all weather conditions: The SHM 31 operates with a visible, easy-to-measure measuring beam. The snow depth is given up to 15 meters within seconds, millimeter-accurate and reliable. Various heating functions significantly extend the lifetime of the laser diode and allow high-quality measurement data in all weather conditions. Regular maintenance becomes redundant with the SHM 31. A very robust housing and an elaborate operation principle allows almost no maintenance work throughout the lifetime of the sensor.
- Parameters measured: Snow depth
- Measurement technology: opto-electronic measuring technique (rangefinder; laser distance sensor) with eye-safe laser
- Product highlights: Determination of snow depth over long distances, heating options allow high quality measurements in all weather conditions, simplified installation due to automatic inclination angle compensation
- Interfaces: RS485 & RS232 with UMB, UMB-ASCII 2.0 & SDI12 protocol
- Article number: 8365.30
- Measurement of millimeter-accurate snow levels over long distances
- Various heating functions significantly extend the lifetime of the laser diode and allow high-quality measurement data in all weather conditions
- Compact and weatherproof housing
- Built-in automatic angle meter allows simplified installation.
- Effective suppression of scattered light
- Differentiation between snow and other natural surfaces
- Optical measuring method is independent of temperature or wind fluctuations and thus offers a great advantage over conventional ultrasonic sensors
- Maintenance-free operation: no calibration or exchange of desiccant
- Part of (alpine) meteorological observation stations from weather services around the world
- Traffic and aviation safety, road surveillance
- Snow level detection for winter sport areas
- Water & energy related applications/industry
The new Lufft SHM 31 snow height sensor is an extension of the successful SHM 30, which still is in operation in networks of numerous National Meteorological Services, institutes and other agencies.
What are the main differences of the Lufft SHM31 compared to the Lufft SHM 30?
Both the extended heating function and the improved design of the laser diode (particularly the laser output) increase the resistance and performance of the sensor in extreme weather conditions, e.g. in severe snow storms or during sudden extreme cold snaps.
New features are, in particular, an energy-saving low-current operation for idle phases, an additional window heater for the laser output, and a built-in automatic angle meter, which allows simplified installation.
Furthermore, the communication interface has been adapted to enable RS-485 and SDI-12 operation. The Lufft UMB Protocol has been included, too.
The SHM31 is based on an opto-electronic laser distance sensor and operates with a visible, easy-to-measure measuring beam. Distances of up to 30 meters to natural, diffuse reflective surfaces are measured very precisely.
The snow depth is given up to 15 meters within seconds, millimeter-accurate and reliable. An additional function as a ground-snow detector is provided by the signal intensity.
The optical measuring method is independent of temperature fluctuations and thus offers a great advantage over conventional ultrasonic sensors. Temporary impairments of the measuring process, for example by precipitation, are compensated by the operating mode.
Another major benefit is that regular maintenance becomes redundant with the SHM31. A very robust housing and an elaborate operation principle allow almost no maintenance work throughout the lifetime of the sensor. No special interventions like frequent replacements of desiccant or regular calibration are needed.
- Dimensions (LxWxH): 302mm × 130mm × 234mm
- Weight: 2,35 kg
- Operating parameters:
- Temperature range: -40°C...+50 °C
- Relative humidity: 0%...100%
- Snow Depth: 0 ... 15 m
- Mounting distance to surface: 0,1 ... 16 m
- Accuracy (snow depth)2: ± (5 mm + 0.06 %)
- Repeatability: 0.6 mm
- Intermediate precision/ reproducibility: 5 mm
- RS485: ASCII, UMB protocol
- RS232: ASCII protocol
- SDI-12: SDI-12 protocol
- Data transfer mode: Polling (UMB, ASCII, SDI-12); Auto telegram output (ASCII)
- typ. power consumption at 24 Vdc and 10 s laser measurement interval: without heater: approx. 0.7 W; with window heating: approx. 3.4 W
- Power supply: 12, 24 VDC
- Maximum power consumption(connecting power with heater on): 18 W
- Laser classification: Laser class 2 (IEC 60825-1:2014)
- Protection class: IP68
- EMC: EN 61326-1:2012 (industrial standard)
- EC: 2014/30/EU & RoHS 2011/65/EU