User's Guide _______________________________________________________________________
142 __________________________________________________________________ M210243en-A
supplies an adjustable constant head of water and allows for accurate
calibration of the rain gauge.
Manufacturer also provides a re-calibration and overhaul service to
customers; however, this section describes a good alternative for re-
calibrating the rain gauge if the user wishes to do so.
Static Calibration
1.
Before re-calibrating the rain gauge take this opportunity to
carry out any other maintenance that may be required.
2.
Install the gauge over a sink as illustrated in Figure 117 below,
ensuring that it is correctly leveled (the RGB1 base plate can be
used for this).
3.
Using a burette or pipette, slowly drip in 10.13 cm
3
of water for
0.2 mm/tip. The bucket should tip on the last drip of water.
Adjust the relevant thumb screw, (located under each bucket)
until the above condition is met. Repeat the procedure for other
side of the bucket.
PIPETTE
OR
BURETTE
LEVEL GAUGE
BY USING
ADJUSTING SCREWS
SINK
9901-031
Figure 117
Static Calibration
It is not possible to set the screws very precisely using this method,
but it should be done with as much care as possible. It is obviously
very important that both buckets tip in response to the same amount of
water. Many manufacturers and users of tipping bucket rain gauges try
to adjust the buckets settings until exactly the correct calibration is
achieved. However, a dynamic test is required to check this calibration
precisely after each readjustment and the process becomes very time-
