Alain Pochon and Ludovic Savoy, both hydro-geologists at Hydro-Géol S.àr.l. (http://www.hydro-geol.ch ) are both long-time users of Tetraedre products.

For the project in Annemasse, they use a TRMC-5 with an STS pressure sensor and a McVan turbidity sensor. The goal is to measure the level and the quality of the water deep down a cave. The sensors have been installed 165m below the surface. Measurements are performed every 30 minutes and GPRS data transmission on the french network take place every 6 hours.

"Thanks to Tetraedre's system, we are able to follow in near real-time the water level and the particles concentration in the cave. In December 2009, the level rose from 100m within 2 days. We even observed a rise of 60m in 9 hours ! The long-term goal of this system is to reduce clogging of the ultra-filtration system installed 2km further, in a drinking water collector" tells Ludovic Savoy.

"This kind of system allows us to be permanently informed of the current measurements and to program, if required an alarm SMS when a critical level is reached. Applications are numerous: Prevent speleologists in case of water rise in a cave or water quality monitoring in a river or in a collector. Tetraedre's solution reduces also drastically travels which is very profitable !"