Study types and specifications of different rain gauges.

1. RAIN
GAUGES
Presented By
Prof. S. R. Satpute

2. RAIN GAUGE
 A rain gauge is an artifact used in
meteorological stations to help
measure and collect precipitations
that fall in a certain place.
 Precipitations are all hydrometeor
falling to the earth from the
atmosphere, including rain, drizzle,
hail, snow and sleet, fog etc.
 There are two types of rain gauges,
non-recording type and recording
type.
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3. NON-RECORDING TYPE RAIN-GAUGE:
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 It gives only total rainfall occurred during particular
time period.
 most commonly used type is Symon’s rain-gauge.

4. SYMON‘S RAIN GAUGE
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 It gives the total rainfall that
has occurred at a particular
period.
 It essentially consists of a
circular collecting area 127
mm in diameter connected to
a funnel.
 The funnel discharges the
rainfall into a receiving vessel.
 The funnel and the receiving
vessel are housed in a
metallic container.

5. RECORDING TYPE RAIN GAUGES
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 These are rain gauges which can give a permanent,
automatic rainfall record in the form of a pen mounted
on a clock driven chart.
 From the chart intensity or rate of rainfall in cm per
hour or 6 hrs, 12 hrs and total amount of rainfall can
be obtained.
There are three types of recording rain gauges
 Weighing bucket type
 Tipping bucket type
 Floating or natural syphon type rain gauge

6. ADVANTAGES OF RECORDING RAIN GAUGES
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 Necessity of an attendant does not arise
 Intensity of rainfall at anytime as well as total rainfall is
obtained,
 Data from in accessible places can be continuously
obtained once gauge is
 established.
 Human errors are eliminated.
 Capacity of gauges is large.
 Time intervals are also recorded.

7. DISADVANTAGES OF RECORDING RAIN GAUGES
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 High initial investment cost.
 Recording is not reliable when faults in gauge arise
(mechanical or electrical) till faults are corrected.

8. WEIGHING BUCKET TYPE RAIN GAUGE
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 It is most common self-recording rain gauge.
 It consists of a receiver bucket supported by a spring or
lever balance or some other weighing mechanism.
 The movement of bucket due to its increasing weight is
transmitted to a pen which traces record or some
marking on a clock driven chart.
 The instrument gives a plot of the accumulated rainfall
values against the elapsed time and the curve so
formed is called the mass curve.

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10. TIPPING BUCKET TYPE RAIN GAUGE
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 It is a 30cm sized circular rain gauge adopted for use by
US weather bureau.
 It has 30cm diameter sharp edged receiver and at the
end of the receiver is provided a funnel.
 Pair of buckets are pivoted under this funnel in such a
manner that when one bucket receives 0.25mm of
precipitation it tips discharging its rainfall into the
container, bringing the other bucket under the funnel.

11.  tipping of bucket completes an electric circuit
causing the movement of pen to mark on clock
driven receiving drum which carries a recorded
sheet.
 These electric pulses generated are recorded at the
control room far away from the rain gauge station.
 This instrument is further suited for digitalizing the
output signal.
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13. FLOATING OR NATURAL SYPHON TYPE
RAIN GAUGE
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 The working of this type of rain gauge is similar to
weighing bucket rain gauge.
 A funnel receives the water which is collected in a
rectangular container.
 A float is provided at the bottom of container, and
this float raises as the water level rises in the
container.
 Its movement being recorded by a pen moving on a
recording drum actuated by a clock work.

14.  When water rises, syphon releases the water
outwards through the connecting pipe, thus all
water in box is drained out.
 This rain gauge is adopted as the standard
recording rain gauge in India.
 curve drawn using this data is known as mass
curve of rain fall.
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16. THANK YOU
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