Xylem RG200 RAIN GAUGE, 6 inch (TIPPING BUCKET) - Manual (Page 5)

Global Water
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Installation of Tipping Bucket with the GL500 Data Logger
e. Pass the Tipping Bucket cable through an unused strain relief. Attach
the two wires to the pulse channel of the GL500.
Installation of Tipping Bucket with other Global Water products
f. The Tipping Bucket comes with an attached RCA jack. Review the
literature for the other product to determine where the Tipping Bucket
RCA jack should be plugged into.
IV. Tipping Bucket Calibration Information
a. Accurate calibration can be obtained only with laboratory equipment,
but an approximate field check can be easily made. The tipping
bucket mechanism is a simple and highly reliable device. Any
accumulation of foreign material, dust, etc. will alter the calibration of
the unit. The tipping bucket must be calibrated with the rate of flow of
water through the tipping bucket mechanism. At least 36 seconds
should be allowed to fill one side of the tipping bucket. This
represents a maximum flow rate of one inch of rain per hour. If the
flow rate is increased, the unit will read low (if properly calibrated).
Decreasing the rate of flow will not affect the calibration. Some time is
required for the bucket to tip (a few milliseconds). During the first 50%
of this tipping time, water continues to flow into the filled bucket; the
last 50% of this tipping time, water flows into the empty bucket. The
amount of water flowing during the first 50% of time is the error, the
faster the flow rate the greater the error. At flow rates of one inch per
hour or less, the water actually drips into the bucket rather than
flowing. Under these conditions, the bucket tips between drips and
there is no error in the readings.