Great Plains 3P806NT Material Rate - Manual (Page 8)

6 3P806NT Table of Contents Main Box Rates Great Plains Manufacturing, Inc.
151-143B Table of Contents Main Box Rates 2011-10-21
Main/Dual Box Seed Rate Calibration
Differences will exist between the tested seed and field
conditions used to generate the Seed Rate Charts, and
your seed and conditions. To accurately achieve your
target population, Great Plains recommends calibrating.
Due to the large number of crank revolutions per acre
(310 or 569) and per hectare (766 or 1405), a practical
calibration is a simulation of
1 ⁄
10
th
acre or
1 ⁄
10
th
hectare.
1. Estimate the sample sizes.
2. To perform this calibration, you need a scale that is
accurate at the aggregate sample size, and three (3)
light containers, each capable of holding the
expected SamplePerRow. Record the empty
container weights.
3. Raise the drill so the gauge wheel is out of ground
contact.
4. Remove the calibration crank from its storage stob.
Store the retaining pin on the stob.
5. Place the hex socket of the crank on the end of the
gearbox input jackshaft (see page 2).
6. Pull the seed hoses off the top of three opener seed
tubes, at the top of the openers. Place the hoses into
each sample container.
7. If not already done, set the Drive Type, Seed Rate
Handle and Seed Cup Doors across the drill. If any
optional seed boxes are loaded, disconnect their
drive or set their rate to zero (unless you are
simultaneously calibrating multiple boxes).
8. Load seed above the rows to be sampled. Load well
more than the expected sample size.
9. Rotate the crank or tire several turns to ensure that
the drives and seed cups are engaged, working
properly, free from foreign material, and that seed is
flowing steadily from the meters. Stop.
10. Note the current reading of the acremeter, unless
you do not plan to rely on it for the calibration.
11. Empty the sample containers back into the seed box,
and place them back under the three hoses to gather
metered seed.
Example: You want to apply barley at a TargetRate of
60 pounds per acre. RateSample is:
Example: the drill has 13 rows. SamplePerRow is:
Example: 3 rows are to be used in the sampling.
ExpectedSample is:
The expected sample net weight is 1.2 lb.
6.0
60
10
------
=
0.46
6.0
13
--------
=
1.38 0.46 3 × =
RateSample
TargetRate
10
----------------------------- =
SamplePerRow
RateSample
RowCount
----------------------------------- =
ExpectedSample SamplePerRow SampledRows ×
=
Example: 3 containers, each weighing 0.5lb:
ContainerWeight = 1.5 lb
Crushing Hazard:
Install lift cylinder lock(s) on a raised drill.
Note: You can also rotate the tire, the gauge wheel
jackshaft or the gear box jackshaft. If using a
non-standard rotating/cranking point, rely on the
acremeter to determine the area simulated.
Example: you desire to plant barley at:
60 pounds per acre
which is between
45 and 50
on the Drive Type 2 chart.
Use an initial Seed Rate Handle (InitialHandle) scale
setting of:
48