horsch LEEB PT 330, Operating Instructions Manual

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14.9 Calibrating the flow
meter
The flow meter is calibrated by using the tank
method. A major amount of water is thereby dis-
charged from the tank over a certain period of time.
With the help of a simulated travel speed and the
spraying duration one can calculate the distance
the machine will travel.
Distance = travel speed x spraying duration
Multiplied with the working width gives you the
area that would be processed when working with
the simulated travel speed and spraying time.
Processed area = distance x working width
You can then calculate the required amount of
spraying mixture and compare it with the actu-
ally used amount.
Required spraying quantity = processed area x
placing quantity
The correction factor for the set pulses/100 l is
thereby determined. This is the required quan-
tity, divided by the actually applied quantity.
required quantity
placed quantity
Correction factor =
¾
The value is finally corrected under parameter
457 and a new calibration is made by using
the new values.
For the PT 330 the standard value is
2,100 pulses/100 l.
Example:
The numerical values in the example were
randomly chosen and may differ from practice.
•
Machine with 36 m working width.
•
Setting on terminal: 2,100 pulses / 100 l
¾
Set 200 l / ha as placing quantity.
¾
Set 10 km/h as simulated travel speed.
¾
Write down the filling level indicated by the
tank control.
¾
Read the value under parameter 457
(pulses/100 l) in the terminal and write it down.
¾
Switch on the sprayer and run it for 15 minutes.
The distance thereby is:
10 km/h x 0.25 h = 2,500 m
Multiplying this with the working width gives you
a processed area of:
2,500 m x 36 m = 90,000 m
2
= 9 ha
The product of this area and the set placing
quantity results in the required amount of spray-
ing mixture:
9 ha x 200 l/ha = 1,800 l
This value is now set into relation to the actually
placed quantity. The actually placed quantity is
the difference in filling level of the Tank-Control
before and after calibration.
Here the actually placed quantity is: 1,850 l
The correction factor in this case is:
1,800 l
1,850 l
Correction factor = = 0.973
The placed quantity is too high, the value under
parameter 457 therefore needs to be corrected.
New value (pulses/100 l):
2,100 x 0.973 = 2,043
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