Instrument : Impact Disdrometer (DISDROMETER)

Instrument Categories
Surface Meteorology

Picture of the Distromet disdrometer

General Overview

The Distromet disdrometer (model RD-80) measures the character and amount of liquid precipitation and is located next to the tipping bucket rain gauge. The main purpose of the disdrometer is to measure drop size distribution, which it captures over 20 size classes from 0.3mm to 5.4mm, and to determine rain rate. Disdrometer results can also be used to infer several properties including drop number density, radar reflectivity, liquid water content, and energy flux. Two coefficients, N0 and Λ, are routinely calculated from an exponential fit between drop diameter and drop number density.

Rain that falls on the disdrometer sensor moves a plunger on a vertical axis. The disdrometer transforms the plunger motion into electrical impulses whose strength is proportional to drop diameter. Data are collected once a minute.

Output Datastreams

  • disdrometer : Disdrometer: measures rain drop size distribution

Primary Measurements

The following measurements are those considered scientifically relevant.


Southern Great Plains
SGPC1 Browse Data Browse PlotsCentral Facility, Lamont, OK
Tropical Western Pacific
TWPC3 Browse Data Browse PlotsCentral Facility, Darwin, Australia retired
 retired = Originating instrument has been retired at this location


Mary Jane Bartholomew
Brookhaven National Laboratory
(631) 344-2444