Great Plains 800 Material Rate - Manual (Page 38)

36 800 Table of Contents Main Box Rates Great Plains Manufacturing, Inc.
175-057B Table of Contents Main Box Rates 2011-10-25
9. Rotate the crank several turns counter-clockwise to
ensure that the drive and meters are engaged,
working properly, free from foreign material, and that
material is flowing steadily from the meters. Stop.
10. Note the current reading of the acremeter, unless
you do not plan to rely on it for the calibration.
11. Empty the sample containers back into the fertilizer
box, and place them back under the three hoses to
gather metered material.
12. Turn crank at a steady rate until one tenth acre or
hectare is tallied on acremeter. While turning, check
that cups have ample seed coming into them.
13. Weigh metered material. Subtract initial weight of
container(s).
14. Divide the net material weight by the number of
sampled rows. Multiply by number of openers on
your drill, and then by 10 if a
1 ⁄
10
th
sampling was
used) to determine the total of pounds per acre
applied.
15. Divide the desired original field rate by the measured
rate to calculate a scale adjustment factor.
16. Multiply the scale setting just used times correction
factor to obtain the next scale setting to use.
17. Reset the fertilizer rate adjuster based on the
settings at the new chart rate.
18. You may want to repeat calibration procedure at the
new setting if your results varied greatly from the
desired field rate.
19. With calibration complete, store the calibration crank,
re-engage the lock-out hub, re-install any seed chain
removed and reconnect fertilizer hoses.
20. Check that your end-wheel tires are 700-15 LT, 4-ply
Rib Implement and properly inflated. See “Tire
Inflation Chart” in the Operator manual.
21. When drilling, check application rate by noting acres
drilled, amount of fertilizer added to drill and fertilizer
level in drill box. If you are applying more or less than
desired, adjust rate slightly to compensate for field
conditions.
Row Spacing Rotations Per Acre (ha)
6 in. (15.2cm) 728 (1799) rotations
7
1 ⁄
2
in. (19.1cm) 728 (1799) rotations
Rotations for one tenth acre is:
72.8
Example:
the three containers weighed a total of
4.55 pounds after test. NetWeight is 3.05 lbs
3.05 4.55 1.5 – = NetWeight GrossWeight ContainerWeights – =
Example:
a 12-row (7
1 ⁄
2
in.) drill, MeasuredRate is 122 lbs/ac
122
3.05
3
----------- 12 Ч 10 Ч =
MeasuredRate
NetWeight
SampledRows
------------------------------------- RowCount Ч 10 Ч =
Example: the target rate was 109 lbs/ac:
the correction factor =0.89
0.89
109
122
---------
=
CorrectionFactor
FieldRate
MeasuredRate
--------------------------------------
=
Example: the previous scale setting was 60,
the next scale setting is 54
54 60 0.89 × =
NextScale PreviousScale CorrectionFactor Ч =