Tipping bucket

(not a photo of our gauges -- ours had an adjustable level base)

A tipping bucket measures rain in increments of 0.01" of water as it accumulates.  Rain enters the gauge through the top opening.  The gauge is calibrated in the lab by dripping water into the tipping mechanism and adjusting mechanical screws until proper operation is obtained.  ISFS tried using these in winter as well, using Lexan Alter screens to increase the snow capture efficiency, but had limited success.  Even for rain, these gauges often became clogged by insects, vegetation, or other matter that got into the gauge.  ISFS has now replaced these by optical disdrometers.