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7.2. Calibrating the rain sensor
The rainfall measuring system is delivered from the factory with high accuracy,
so that normally no calibration is required.
Calibration is only necessary when very high accuracy is required.
Before beginning to calibrate the rainfall measurement recorder, reset any total
rainfall quantity that may be indicated in the normal display mode back to zero
(press and hold the "RAIN" key down for about 2 s in normal display mode - when
the key is released, the total rainfall quantity will be zero. Set the units for rainfall
measurement to display in l/m
2
. See section 3.1 to set the units).
For the exact calibration proceed as follows:
1. Over a ten-minute period slowly pour 100 ml (3,38 oz.) of water into the rain
sensor collector funnel.
CAUTION!
Pouring quickly will falsify the measurement result! Slowly pour the water
into the funnel so water is at no time resting in the funnel.
2. The total amount displayed should be 6.5 l/m
2
.
3. If a different value is displayed, then the rocker value should be recalculated as
follows:
New rocker value =
6.5 x current rocker value
Actual value (display when filled with water)
The new rocker value must now be entered in the configuration menu (see 3.1). It is
always given in ml/rocker stroke,
the units on the right are the units for the
subsequent display of rainfall!
The factory setting is 295 ml/rocker stroke.
