Rain enters gauge through an orifice (200 cm2), protected by distortion-preventing aluminum ring. Resolution is 1 mm, 0.2 mm or 0.1 mm (WMO standard). Optional heater assembly for extremely cold environments.

The radar-precipitation sensor is equipped with a 24 GHz doppler-radar in order to measure the spped of rain or snow drops. Due to the correlation of drop size and speed, the precipitation amount is calculated. Maintenance-free.