Great Plains NTA2007HD Operator Manual - Manual (Page 82)

78 Great Plains Manufacturing, Inc. Contents Index NTA607/2007HD
166-283M Contents Index 04/04/2011
Variable Rate (Servo) Calibration
Note: For drills with manual (crank set) gearboxes, use
the instructions at “Calibration for Manual Gear-
box” on page 75.
Complete step 1 through step 13 beginning on page 73,
and “ACC Re-Configuration” from the Variable Rate
Kit manual 166-263M. You must have created or
selected a Material that matches the material you are
about to calibrate.
34. Check that final Range gear pairing is the same on:
• the chart,
• the meter, and
• the Meter gear Range in the Channel Setup.
35. Enter the calibration screen for the Channel
assigned to the meter to be calibrated.
At this time, the linear actuator for that meter’s gear-
box becomes active. The scale indicator moves to
approximately mid-scale, then stops.
Pointing to a specific value is not required, but it
needs to be in the range 30
° to 95°. Great Plains
recommends using a scale setting that is close to
your expected target rate.
Use the Inc+/Dec- softkeys on the monitor console to
adjust the indicator to the seed rate chart Gearbox
Setting value, or at least to within the 30
°-95° range.
36. Manually crank the meter for at least the number of
turns shown in the table at right for
1 ⁄
10
ha or
1 ⁄
10
ac.
The exact number of revolutions, cranking rate, and
precise starting and stopping handle angles are not
critical, as the system reads meter revolutions accu-
rately, and can compensate for shaft speed, seed
size and partial turns.
What matters is getting a large sample, to reduce
errors and increase confidence in the calibration.
Note: By calibrating at or near target rate, and for
1 ⁄
10
ha,
you establish a comfort level that the drill is set up
correctly, in particular, that you are in the correct
gear Range for the desired application rate.
Note: If no “Variable Cal Const” was selected during ma-
terial setup, crank at 1
1 ⁄
2
revolutions per second
(90 rpm) for most accurate results.
Null4:
Seeding Example; Initial Calibration Screen:
Servo Seeding Example: Calibration Targets:
Crop: Wheat
Flutes: 2 Stars
Target Seed 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
Parameter Value Comment
CHANNEL 1 Example
Material Wheat HRW Example
Density 0.79 KG/L Example
Calibration
Constant
77591 PUL/FT
From chart
Target Meter
rpm
20 RPM
Example
# Meter
Revs
30 REV
Example
Pulse Count 0 PUL Pre-Cal.
New Calib
Const
______ PUL/FT
Total #
Towers
4
Per Imple-
ment
Amount
Dispensed
______ LBS
From Scale
Calibration Crank Revolutions
Limited Flex NTA607HD
Revolutions per Hectare 862
Revolutions per 1/10th hectare 86.2
Calibration Crank Revolutions
Limited Flex NTA2007HD
Revolutions per Acre 349
Revolutions per 1/10th acre 34.9