Great Plains Fertilizer Arm Kits - Manual (Page 10)

204-326M 7/31/2002
8
ACREAGE CHART BASIC CALIBRATION
To double check the accuracy of your application
rate, check the following instructions:
1. Measure 200’ and determine the number of
seconds required to travel this distance under
field conditions with implements in working
condition. EXAMPLE: It takes 7 seconds to
travel the 200’ which equals 5 mph.
2. Place graduated container or pre-weighed
container under one nozzle and catch the dis-
charge for 1 minute. Divide 128 into the num-
ber of fluid ounces caught. 128 fluid ounces
equals one gallon. EXAMPLE: 64 ounces
caught in one minute.
64.0
÷
128 =.50 gallons/minute
3. Determine your nozzle spacing in inches.
EXAMPLE: 1 nozzle every 40".
SOLUTION:
Gallons per acre = 5940 x Gallon per minute
Nozzle spacing in inches x
Miles Per Hour
GPA = 5940 x.50
40 x 5
GPA = 2970
200
GPA = 14.9
The above information will assure you of a check
for accurate application in the event there is an er-
ror in the gauge nozzle spacing, nozzle height,
tractor speed or nozzle wear.
Calibration and Application Rates
MILES PER HOUR CALIBRATION
If tractor does not have a speedometer, determine tractor
speed by using the following chart:
See application chart when M.P.H. is obtained.
1. Determine nozzle size and desired spraying pressure
using the application guide on page 9.
2. Find fluid gallons per minute in the chart on page 9.
3. Catch flow at pressure desired for 1 minute {for large
nozzles catch the flow for 30 seconds and multiply by 2}.
4. If the gallons per minute caught are within the limit in the
chart on page 9, the nozzle is accurate and G.P.A. charts
should be followed.
5. if the nozzle is not within the limit, check for obstructions
or wear in the orifices of the nozzle. Take the cap off the
nozzle, clean the orifices with a toothpick and retest. If
several nozzles test the same, but are not within the lim-
its, a faulty gauge may be the problem. Replace pres-
sure gauge with a new gauge.
6. For heavier solutions use density flow chart on page 11.
MPH SECONDS TO TRAVEL
200 FEET
2.5 55
3.0 45
3.5 39
4.0 34
4.5 30
5.0 27
6.0 23
7.0 19
8.0 17
9.0 15
10.0 14
11.0 12.5
12.0 11.5