
Great Plains | 151-144B | 2019/03/14 8
3P1006NT Table of Contents Main and Dual Seed
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 more
accurately reach your target population, calibrating is
recommended.
Due to the large number of crank revolutions per
hectare (acre), a practical calibration is one-tenth
hectare (acre).
How to estimate the sample sizes:
Example
Calibration Procedure
To perform this calibration, you need a scale and
three light-weight containers, each capable of
holding the expected SamplePerRow.
Weigh the empty containers.
To calibrate use either the tire or the calibration
crank. If using the calibration crank, see “Calibration
Crank” on page 2 for the correct crank location. If
using a non-standard rotating/cranking point, rely on
the acremeter to determine the area.
Crushing Hazard
Install cylinder lock on a raised drill to
prevent injury should hydraulic system allow
drill to lower while working around it.
1. Raise the drill so the gauge wheel does not
contact the ground. Install cylinder lock.
If the gauge wheel is in contact with the
ground, cranking will be difficult or
impossible.
2. For dual seed calibration on drills with
S/N A1211W and above, unpin the coupler and
slide out of the way to disconnect the two
jackshafts (see “Calibration Preparation for
S/N A1211W+” on page 3).
3. Remove the calibration crank from storage and
place the crank on the end of the appropriate
jackshaft.
4. Pull the seed hoses off the top of three openers
and place a hose end into each sample
container.
5. Set the drive type and seed rate handle.
6. Set seed cup doors across the drill.
7. Disconnect the drive on any optional attachments
that are loaded or set the rate to zero (unless you
are calibrating multiple boxes at the same time).
8. Load seed above the rows to be sampled. Load
more than the expected sample size.
9. Rotate the crank or gauge wheelseveral turns to
make sure the drives and seed cups are
engaged, working properly, free from foreign
material, and that seed is flowing steadily from
the meters.
10. Note the current reading of the acremeter if using
it for the calibration.
11. Empty the sample containers back into the seed
box. Place the containers back under the three
hoses to gather the metered seed.
12. Turn the crank at a steady rate for the number of
turns specified at “Calibration Crank
Revolutions” on page 3, or until one tenth of the
area is counted on the acremeter. While turning,
check that cups have seed coming into them.
13. Weigh metered seed and subtract initial weight of
container(s).
Metric Non-Metric
Seed Type Barley Barley
TargetRate 67 kg/hectare 60 lb/acre
RateSample
RowCount 15 15
SamplePerRow
SampledRows 3 3
ExpectedSample
RateSample TetRatearg
10
---------------------------------
=
SamplePerRow RateSample
RowCount
------------------------------------
=
ExpectedSample SamplePerRow SampledRows=
ContainerWeight WeightPerContainer Containers=
NetWeight GrossWeight ContainerWeight–=