Operating instructions

66 YP2425F/YP4025F Table of Contents Index Great Plains Manufacturing, Inc.
403-362M Table of Contents Index 2013-03-25
Density Adjustment
If your material (seed or fertilizer) has a density that is
materially different from the reference material listed at
the top of each chart, you can compensate for it.
Density variance is only one of many factors that can
cause an actual rate to vary from a chart rate.
Compensating your initial target rate helps reduce the
error, but rely on calibration for the most accurate field
results.
In this example, the target fertilizer application rate is 120
kilograms per hectare.
1. Weigh a known volume of your material, and
compute the density in the same units used in the
table, kilograms per liter (pounds per bushel or
pounds per cubic foot). Be sure to subtract out the
container weight.
2. Divide the reference material density by the
measured actual material density, to obtain a
correction factor.
3. Multiply the target field rate by the factor to yield an
adjusted chart rate.
4. Look up the adjusted rate in the chart, and use the
settings for it.
Note: If the adjusted chart rate would correspond to an
apparent variable rate gearbox setting below 20,
use another chart (Low Range chart or lower Flute
Stars chart).
Example:
Target fertilizer rate is 120 kilograms per hectare
The chart was based on 0.96 kg/l reference material that
is 134% heavier. If the chart value for “120” (a variable
rate gearbox setting of 45,) is used, too much material
will be applied.
Example:
10 liters of your material weighs 14 kg.
Your material density is: 14 ÷ 10
which is: 1.4 kg per liter
Example:
reference material: 0.96 kg/l
factor: 0.96 ÷ 1.4
which is: 68.6%
Factor
ReferenceMaterialDensity
MeasuredMaterialDensity
-----------------------------------------------------------------
=
Example:
if the target field rate is 120 kilograms per hectare, the
adjusted chart rate is:
120 x .686
which is an adjusted target rate of:
82 kilograms per hectare
AdjustedRate FieldRate Factor×=
Example:
Look up 82.
Closest chart value is 90
Use those settings:
High Range
Gearbox 40
Be sure to calibrate (page 25), to verify the adjustment
and setting.