Brookhaven National Laboratory
The impact disdrometer collects observations of the drop size spectra of rainfall. The sensor transforms the mechanical impact of each drop into an electrical pulse. With calibration, the size of each pulse is interpreted as the diameter of the observed drop.
ARM also deploys laser disdrometers (LDIS) and video disdrometers (VDIS). Data from all these instruments help improve the quantitative description of precipitation processes in climate models.