Snow weight - snow pillow

Meteorological station with pillow in the Kaunertal, Alps, Austria

Snow pillow and ultra sonic sensor

Parameter to be measured:

snow water equivalent

Method:

Snow pillow with pressure sensor

The working principle of the snow pillow is based on the measuring of the hydrostatic pressure caused by the layer of snow. The snow on top of the snow pillow is detected by a pressure transmitter connected to the system, which converts the data into an analog signal corresponding to the water-content equivalent of the snow covering. The additional detection of snow-depth with an ultrasonic snow-depth sensor permits automatic calculation of the average density of the layer of snow. Especially in regions with huge amount of snow it is recommend to use a snow pillow with large dimensions (e.g. 3 x 3m) to pillow prevent any bridging that might occur within the snow covering and cause an effect on the measurement readings.

Equipment:

Snow Pillow: for example Sommer Mess-Systemtechnik

Antifreeze solution: ethylene glycol from Sigma-Aldrich (about 1000€). But other solutions may be cheaper or less toxic.

Logger: DL2E Data Logger from DeltaT

Advantages:

Continous measurements

Disadvantages:

Expensive
Effort during installation
Antifreeze solution is hazardous to waters

Problems/Questions:

Installation

The following requirements must be observed in order to ensure that the snow pillow produces accurate readings. The measuring area must be horizontal, flat and protected from the wind in order to provide a representative section of snow. Do not select as a measuring field an area in the immediate vicinity of steep slopes, sudden drops in terrain or large boulders, as snow movements in these areas can have an effect on measurement readings.

Links

Projects that used the above equipment

Other related web sites

References