Material Rate User Manual
80 1625AHD/AHL Table of Contents Great Plains Manufacturing, Inc.
411-020B Table of Contents 2014-03-17
11. Operate the crank, at one to two revolutions per
second, for the number of revolutions shown in the
table at right.
Machine Damage and Rate Risks:
Rotate calibration crank only in the COUNTERCLOCKWISE
direction. Operating in reverse can cause gearbox damage.
Note: A longer calibration is always more accurate,
especially for low rates and small seeds.
1
⁄
10
hectare or acre is easy to calculate and is a
minimum calibration run.
The right column contains the starting values of an
example for the following steps, in Metric and U.S.
customary (“USc”) units.
12. Accurately weigh the bag plus material. Subtract the
empty bag weight to determine the application rate
for
1
⁄
10
hectare (or
1
⁄
10
acre).
13. Multiply the sample size by 10 to determine
application rate per hectare (acre) at the current
variable rate gearbox setting.
If the calibrated rate matches the target rate, skip to
step 18. Otherwise…
Planter Crank Revolutions Per
Model 1/10th Hectare 1/10th Acre
1625AHD-1236 97.2 39.3
1625AHD-1630 87.5 35.4
1625AHD-1636 72.9 29.5
1625AHD-1670 95.2 38.5
1625AHD-1675 88.9 36.0
1625AHD-2420 87.5 35.4
1625AHD-24TR36 97.2 39.3
1625AHD-32TR30 87.5 35.4
1625AHD-32TR36 72.9 29.5
1625AHD-32TR70 95.2 38.5
1625AHD-32TR75 88.9 36.0
36188Z
Metric Example: USc Example:
Model: 1625AHD-1670 Model: 1625AHD-1630
Application FieldRate:
104 kg/ha
Density AdjustedRate:
83.2
Application FieldRate:
93 pounds per acre
Density AdjustedRate:
74.4
Initial (adjusted) Variable Rate Gearbox setting:
28 29
Empty Calibration BagWeight:
1.52 Kg 3.36 lbs
Metric Example:
GrossWeight is:
11.2 kg
SampleWeight =
11.2 - 1.53
which is:
9.67 Kg
USc Example:
GrossWeight is:
8.6 pounds
SampleWeight =
12 - 3.36,
which is:
8.6 pounds
SampleWeight GrossWeight BagWeight–=
Metric Example:
CalibratedRate =
6.67 × 10
which is:
96.7 kg/ha
USc Example:
CalibratedRate =
8.6 × 10,
which is:
86 lbs/ac
This is lower than our target field rate of:
104 kg/ha 93 lbs/ac
CalibratedRate SampleWeight 10×=