Great Plains 3N-4025P Operator Manual - Manual (Page 46)

42 3N-40P Table of Contents Index Great Plains Manufacturing, Inc.
196-538M Table of Contents Index 2014-01-29
Seed Rate Calibration
Seed rate calibration consists of:
a. Setting up to collect seed at one
a
or more rows
(typically 3), using an approximate calibration
number.
b. Running the hydraulic drive (with drill stationary) for
a short period of time, twice:
- once to prime the seed cups, and
- once to generate the sample.
c. Weighing the collected seed, and determining
amount per row.
d. Entering that weight on the console. The controller
uses it to calculate a more precise Cal. number.
Tools required:
• small container(s) to capture seed at one or more
openers, and
• a scale with a capacity great enough to weigh the
container(s)+seed, and precise enough to register the
difference between that and the empty container(s).
Seed Rate Calibration Steps
In the steps which follow, the examples are based the
configuration at right.
1. Unfold the drill.
The wing drive shafts cannot turn with the drill
folded. U-joint damage will occur if attempted.
2. Load an amount of seed, equal to about twice the
expected sample size, over one or more rows near
the end of the left wing seed box. The expected
amount of seed is determined by you. The controller
calculates the run-time necessary to generate that
amount at a single row.
Great Plains suggests sampling an amount that is at
least
1 ⁄
4
pound (0.1 kg), and requires at least 100
seconds. At typical planting speeds, this is about one
row for one acre (or one row for half a hectare).
Divide your intended seed rate by your row count.
3. Raise and lock-up the drill if capturing seed below
openers.
a. For short run times and/or small samples, increase the accuracy of the results by sampling multiple rows, and calculating the average.
For adjacent rows, pull the seed hoses off at the opener, and route them to a common collection container.
Figure 41
Calibration: Initial Screen
28251
Example drill configuration:
Model: 3N-4010P-4810
Row spacing: 10 in
RowCount = 48
Seed: long grain rice
Desired seed rate: 50 pounds/acre
Sample size for our example:
SeedRate = 50 (lbs/ac)
RowCount = 48
1.04 = 50 / 48
SampleSize is 1.04 lbs
Load 2 lbs or more for testing.
SampleSize (lbs)
SeedRate
RowCount
------------------------- =
SampleSize (kg)
SeedRate
RowCount 2 Ч
---------------------------------- =