Great Plains NTA2007 Operator Manual - Manual (Page 84)

80 NTA607 or NTA2007 Table of Contents Index Great Plains Manufacturing, Inc.
166-372M Table of Contents Index 2012-01-05
Calibration for Manual Gearbox
Note: For drills with Variable Rate Kit installed, continue
at “Variable Rate (Servo) Calibration” on
page 83.
Complete step 1 through step 13 beginning on page 78.
14. Set gearbox (page 77): Remove the hairpin cotter
securing the gearbox adjustment crank. Rotate crank
until the control arm indicator points to the scale
setting that matches the rate from the Seed Rate
Chart or as determined by any previous calibration of
a similar material for the same rate.
15. Re-insert the hairpin cotter.
16. Turn the calibration crank, counter-clockwise, for
enough turns to be sure the meter flutes are full and
the system is metering.
17. Stop cranking. Wipe meter doors. Sweep any
material in the chute into the bag. Empty the bag.
18. Push and then and then
to get to meter calibration.
19. On the seed monitor terminal,
set the monitor to Calibration mode .
enter [ 5 ] for the “# Meter Revs”, and
press the Start softkey .
This “# Meter Revs” parameter does not affect the
monitor calibration because the monitor counts
actual meter shaft revolutions and uses that count to
compute the Calibration Constant.
The “# Meter Revs” parameter is used for a progress
bar displayed during calibration.
20. Turn the hand crank, counter-clockwise, to simulate
meter operation for
1 ⁄
10
ha or
1 ⁄
10
ac. See table at
right.
Note: It is important to turn the calibration crank rapidly.
Use a comfortable speed of 1 to 1
3 ⁄
4
revolutions
per second, which simulates a planting speed
range of 6.7-11.8 kph (4.2-7.3 mph). A longer
calibration is always more accurate, especially for
low rates and small seeds.
1 ⁄
10
hectare is easy to
calculate with and is a minimum calibration run.
Note: For more accurate results, crank for a full hectare or
acre. With two people, the second person can
observe the revolution count on the seed monitor.
Machine Damage / Invalid Results Risks:
Rotate the hand crank only in the counter-clockwise direction.
Operating in reverse can damage the meter gear box, and
produces low sample sizes leading to incorrect calibration and
excessively high field rates.
Note: The rate of the arm adjusting crank is more than
one scale degree per turn, and the crank can only
be pinned at quarter turns. Pin it when the
indicator is closest to the desired setting.
NTA607 Calibration Crank Revolutions
Revolutions Per Ltd. Flex Std. Flex
Hectare 862 855
1/10th hectare 86.2 85.5
32157
NTA2007 Calibration Crank Revolutions
Revolutions Per Ltd. Flex Std. Flex
Acre 349 346
1/10th Acre 34.9 34.6