The smart radar rain sensor & present weather detector! The Lufft WS100 is our rain sensor with radar technology and adjustable heating. Using a 24-GHz Doppler radar, it measures the speed of all forms of condensed water. These include rain, freezing rain, hail, snow and sleet. The low-energy sensor detects precipitation from the first drop. Its possible uses are nearly unlimited. Whether in hydrology and water management, agricultural and environmental science, building automation, meteorology or airport and traffic control: the rain gauge measures rain almost anywhere in the world.