SHM 30/31 Snow Depth Sensor

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.