Description

The
Self-Recording Rain gauge (SRRG) consists of a rain water collector and a
rainfall recording mechanism mounted on a base. The rainfall measuring unit
consists of a float chamber containing a light metal float and a siphon
chamber.  The chart is wound on rotating
drum driven by mechanical clock which rotates 1 revolution in 25 hours. The
float rises as per the rainfall & so the recording pen also rises plotting
a line of on the chart. When the siphon chamber is filled completely, the water
in it drains out completely called "Siphoning". When siphoning
occurs, the pen fixed on the float rod falls to the zero mark on the chart and
the gauge is ready to record rainfall  again for 10 mm rainfall.