snow gage[′snō ‚gāj]
an instrument for measuring the density of the snow cover. The principal part of a snow gage is a hollow cylinder of a given cross section with a saw-edged bottom. The cylinder is pushed vertically into the snow until it touches the underlying surface; the column of snow is then removed together with the cylinder. The snow sample obtained may be weighed, or the snow may be melted in order to determine the volume of water formed. The density of the snow cover is found by computing the ratio of the weight of the sample to the volume.
Radioactive snow gages are coming into use. They use a source of gamma radiation placed at a certain depth in the snow cover and measure the attenuation of the radiation caused by the snow.