Precipitation covers rain, hail, snow, rime, hoar frost and fog, usually it is measured using precipitation gauges, or rain gauges. The most common types are based on weighing or tipping bucket. However the accuracy of these instruments is most disputed, and there are claims that for many applications one can better use the information of a radar or present weather sensors.
Gauges are made by a large number of manufacturers. A focused manufacturer is Pronamic.
Lufft of Germany has introduced a new rain/precipitation sensor based on 24 GHz doppler radar technology. This sensor type is expected to be a serious competitor to tipping bucket and weighing sensors.
An alternative way of measuring is by analysis of drop size distributions. The name of these is distrometer. Designs are made based on drop mechanical impact by Distromet, based on optical analysis by PMTech and with complete video analysis by Johanneum Research. An "optical rain gauge" is made by Optical Scientific.
There are some manufacturers offering specialized rain sampling systems, offering the possibility to gather precipitation samples day after day. In a later stage chemical analysis can be performed. Manufacturers are Eigenbrodt and MTX.
Rain radars are also manufactured as small systems, see Ellason Weather Radar.
For solid precipitation, see air pollution.
The measurement of dew and leaf wetness is particularly important to agriculture (and the spread of plant disease).
Ice accumulation, fog precipitation and snowfall are hard to measure and no specialized instruments are known to us. Most manufacturers will offer heated versions to solve the problem of measuring under sub-zero temperatures. A specialised Icing sensor is offered by Goodrich.
No specialized manufacturers of dew, leaf wetness and ice accumulation were found. Any suggestions would be appreciated.