Distromet Joss Waldvogel RD-80 Impact Disdrometers are installed at Chilbolton and Sparsholt and work by converting the vertical momentum of a falling drop into signals whose amplitude depends on the diameter of the impacting drop. A conical styrofoam body is used to transmit the mechanical impulse of an impacting drop to a set of two moving coil systems in magnetic fields. They measure drop sizes in 127 size bins from 0.3 to 5.0 mm.
The Chilbolton disdrometers provide an essential link between actual size measurements of rain drops and the drop size information derived from the 3 GHz CAMRa radar.
