Great Plains V-300F Operator Manual - Manual (Page 93)

Great Plains Manufacturing, Inc. Adjustments 89
11/15/2007 148-057M-A
18. Carefully remove the calibration tray. Empty it into
the calibration bag. Weigh the bag.
Note: If the scale was “zeroed” for the bag weight at step
10, the scale reading is the fertilizer weight only.
19. Calculate the rate for a full hectare or acre. Figure
the difference between the measured rate, and the
original target rate (not the density-corrected rate).
20. From the current sprocket setting in the chart, move
up or down in the chart by this difference.
- If the sample rate was high, adjust down.
+ if the sample rate was low, adjust up.
Note: If the sample rate was high, it may be more conve-
nient to use the rate adjuster to reduce it, rather
than changing sprockets.
21. If the change was significant, retest at new setting.
22. Empty the bag into the fertilizer box.
23. Re-insert the tray facing down (to prevent collection
of debris), and swing latch down to secure it.
24. Using the crank handle, push in and turn the fertilizer
meter diverter shaft clockwise, back to normal oper-
ating position.
When drilling, check material rate by noting acres drilled,
amount of material added to drill and material level in drill
box. If you are applying more or less than desired, adjust
rate slightly to compensate for field conditions.
Example:
Sample weight: 13.5 kg
Full hectare rate: 10 x 13.5 = 135 kg
Target rate: 128 kg
Difference: 7 kg
Sample weight was: high
Previous chart rate was: 182.7
Subtract 7 from previous setting
New chart rate: 175.7
Closest chart rate is: 174.0
Use new settings of:
Range: High
Driver: 17T
Driven: 21T
Adjuster Method:
Sample was 7/128 = 5.5% high
Reduced rate as a percentage: 100-5.5 = 94.5%
Adjuster setting for 94.5% = 84.5
Use new sprocket settings, or adjuster 84.5,
and retest.