Calibrating volumetric rate spreader constant – Great Plains YP2425F-2470 Material Rate User Manual
Page 29
Great Plains Manufacturing, Inc.
Volumetric Meter Planting
27
2013-09-23
401-406B
Calibrating Volumetric Rate Spreader Constant
Calibration (which determines the Spreader Constant) is
required for accurate planting of volumetric (GRAN)
seed.
Volumetric seeds are planted at much higher populations
than singulated seeds, and are measured in pounds or
kilograms (rather than seeds) per acre or hectare. The
seed tube sensors are generally not capable of counting
every seed at typical volumetric rates (although they do
report blockage).
For volumetric calibration, the tractor must to be hitched
to the planter, and providing electrical power. Leave all
hydraulic circuits in Neutral until instructed to activate the
drive circuit.
1.
You will need a light weight container for each row
sampled, and a scale that is accurate at the
expected sample weight. Great Plains recommends
using enough rows and/or revolutions to generate a
sample of about 10 pounds (4.5 kg), ideally:
2.
Determine the meter revolutions needed. The
following equation gives the number of meter
revolutions needed to meter 10 pounds. The table on
page 36 provides approximate pounds (and kg) per
revolution of each wheel and seed.
3.
Configure the seed monitor for the planter and crop
(material). If the seed density is not known,
use 1 lb./cu-ft, 1 lb./bu or 1 kg/l.
4.
Consult the rate chart for the crop. Note the allowed
Meter RPM range for the intended seed wheel and
planting speed (see “Reading a Volumetric Chart”
on page 29).
5.
Select the section and rows to be sampled.
6.
Use the clutches to disconnect the other sections of
the planter. This eliminates the need to uncouple the
meters on those sections.
7.
Disengage the drive couplers on all other meters on
the test section, except the meters to be used for
testing.
• Use at least two rows.
• Use no fewer than 5 meter revolutions.
Planter Section Movement Hazard:
Hydraulic circuits are active for calibration. Unexpected
movement of planter mainframe, sections, markers, and
unexpected activation of auxiliary devices can occur if
controls are not correctly pre-set and left untouched.
Keep everyone clear of planter while calibrating.
Population Risk:
Calibrate - Planting volumetric seed based only on chart
data is risky. Your material, and your field results, can vary
substantially from the test material used to generate the
charts. Great Plains strongly recommends calibration.
For Example
4 containers each weighing:
8 oz.
8 oz.
× 4 = 32 oz.
ContainerWeight
2 lbs.
For example:
planter: YP2425-4715, 15 rows
wheel: 403-118D WHEAT NARROW
crop: Hard Red Winter wheat
PoundsPerRev:
0.078
RowsSampled
:
4
10
ч (4 Ч 0.078) = 32
Enter 32 for “# Meter Revs” at step 11 on page 28.
#MeterRevs
10
RowsSampled
PoundsPerRev
×
-------------------------------------------------------------------------
=
For example:
target population: 110 lbs./ac
desired speed: 5 mph
METER RPM
5 rpm minimum, 35 rpm maximum
Target Meter rpm: 30