LE TÉLÉNIVOMÉTRE A FAISCEAU HORIZONTAL MOBILE

Abstract The study of the radioactive snow gauge has been undertaken in Grenoble in 1962 with the objective to develop, up to the routine operation, an automatic solid state electronic snow gauge, radio transmitting every day. 4 units of a first design, with steady vertical radioactive beam have been operated from 1964, but the limitation of the measurable depth to 4 meters of snow, 1,2 meter of water, was soon found too low in the French Alps. A new type of gauge, with moving horizontal beam, profiling the snow pack, was designed in 1965, and evaluated through the last two years—During the measuring cycle, the source (30 millicuries of Cesium 137) and the G.H. detector are moving up at the same level inside two vertical pipes whose distance is 60 cm and height 6 meters; their speed is related to the pulse rate of the detector. One radio signal is emitted each decimeter during the motion. As soon as the team energes from the snow, it stops and returns back to its starting position under the ground level—t...