Calibration of the rainfall reading indicator
The rainfall measuring system is delivered with a very high accuracy, so that normally no calibration is required. A calibration only becomes necessary when very high accuracy is required for professional use or for special purposes.
Before starting the calibration of the rainfall reading indicator, set any existing summed rainfall value in the normal display mode back to zero (see section “Rainfall measurement“).
For the exact calibration proceed as follows:
1.Allow 100 ml of water to trickle continuously and distributed evenly into the funnel over a period of 10 minutes. In doing so, there must be a period of at least 15 seconds between the individual rocker movements. If the rocker tilts more quickly, the amount of water flowing through is too great and the flow must be reduced.
2.After the water has completely run through, it is necessary to wait for a further period of 6 minutes. The total amount indicated should now be 7.5 l/m2.
3.If a different value is displayed, then the rocker value should be recalculated as follows:
New rocker value = 7.5 x current rocker value
Actual value (display when filled with water)
The calibration value of the rainfall per rocker stroke for the rain sensor is shown in touch screen field 8 (top center). 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 300ml/rocker stroke. Please note: This value is reset automatically after an initialization.
-Touch screen field 8 (RAIN) must be pressed in order to set the required value.
-The associated display will now flash:
and the lower touch screen field will change to the following form:
-The required value between 10 and 999 ml/rocker can now be set using the touch screen fields “+” and
-When the required value has been set, you can exit
Setting the rainfall display units
The display units for rainfall are shown in touch screen field 9 on the right hand side next to the calibration value for the rainfall. The factory setting is l/m2.
-By touching field 9 the display units can be switched between l/m2, mm or inches.
Air pressure display correction
If the current relative air pressure at the place of installation is known (meteorological office, Internet, TV weather station, etc.), this can be set up accurately. It deviates from the general air pressure referred to sea level given in weather reports covering large areas depending upon the height above mean sea level. You will find a detailed explanation of this in the section “Explanation of terms”
-Touch screen field 10 (AIR PRESSURE) must be pressed in order to set the current value.
-The associated display will now flash:
and the lower touch screen field will change to the following form:
-The value currently known can now be set using the touch screen fields “+” and
-When the required value has been set, you can exit
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