Great Plains NTA2007 Operator Manual - Manual (Page 82)

78 NTA607 or NTA2007 Table of Contents Index Great Plains Manufacturing, Inc.
166-372M Table of Contents Index 2012-01-05
Meter Calibration
The Seed Rate Charts are based on cleaned untreated
seed of average size and test weight. Many factors affect
meter rates including foreign material, seed treatment,
seed size, field conditions, and test weight. The Dry
Fertilizer Rate Chart is based on a representative
granular fertilizer.
Great Plains recommends calibrating for the exact
materials you intend to apply. Calibration determines two
very important settings for achieving accurate rates:
• The kilograms per hectare (or pounds per acre) of the
meter at the current variable rate gearbox setting for
your particular seed or fertilizer.
• The Calibration Constant for the monitor to accurately
report (or control) the planting rate of your particular
seed or dry fertilizer.
The seed monitor must be setup for the drill, and if a
variable rate kit is installed, there is additional setup for
that. See: “Monitor Material Configuration” on
page 71.
The seed monitor must also be correctly set up for the
material(s), or the calibration will not result in useful
monitor displays, and may cause incorrect application
rates if a variable rate kit is installed.
Calibration: Common First Steps
The calibration is different for manual (crank-adjusted)
and servo (variable rate kit) gearboxes. These first steps
are common to both gearbox types.
The right column contains an example for the following
steps.
1. Raise drill (page 41): This prevents the contact drive
wheel from engaging the transport tire.
2. Turn on the seed monitor.
3. Determine the Range and gearbox settings from the
rate charts.
4. If your material has a density that is significantly
different from that used to generate the chart, you
may want to adjust the density before choosing the
initial gearbox setting and Range.
Agricultural Chemical Hazards:
Obey manufacturer or grower recommendations for safety
equipment and protective gear when using treated seeds.
See the Seed Rate Chart manual for an example in U.S.
customary units.
Seeding Example; Calibration Targets:
Drill: NTA607-4006
Crop: Wheat
Flutes: 2 Stars
Target Rate: 200 kg/ha
Chart Data:
Range: High
Closest Chart Rate: 201.3 kg/ha
Initial Variable Rate Gearbox setting: 62
Initial Calibration Constant: 79197
Fertilizer Example; Density Compensation:
Material: Dry Fertilizer
MaterialDensity: 0.82 kg/litre
TargetRate: 200 kg/ha
Chart Data:
ChartDensity: 0.96 kg/litre
Range: High
Closest Chart Rate: 199.6 kg/ha
Initial Variable Rate Gearbox setting: 60
Initial Calibration Constant: 88063
Adjustment Factor:
Factor = 0.96
÷ 0.82, which is:
1.17
Adjusted Rate = 200
× 1.17, which is:
234 kg/ha
Chart Rate After Density Adjustment:
Range: High
Closest Chart Rate: 235.5 kg/ha
Initial Variable Rate Gearbox setting: 66
Initial Calibration Constant: 90509
Factor
ChartDensity
MaterialDensity
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=
AdjustedRate TargetRate Factor
Ч
=