Great Plains TM700 Operator Manual - Manual (Page 34)

Tractor Mount Sprayer
500-052M 5/13/2003
32
Spraying Solutions Other Than
Water
Calculations are based on spraying water, which weighs
8.34 pounds per US gallon. The following conversion
factors must be used when spraying solutions which are
heavier or lighter than water. In order to determine the
proper size nozzle for the solution to be sprayed, multi-
ply the desired GPM or GPA of solution by the water rate
conversion factor. Then use the new converted GPM or
GPA rate to select the proper size nozzle.
EXAMPLE: It is desired to apply 22 GPA {gallons per
acre} of nitrogen in 30" rows. {28% N, density is 10.65 lb/
gal from the chart above}
From theTable 5, “Density Conversion Table,”, the con-
version factor is 1.13.
GPA {Solution} x Conversion Factor = GPA
(22 gal/acre) (1.13) = 24.86 gal/acre
To choose a nozzle and a pressure, use 24.86 gal/acre
on the nozzle charts.
Weight of
Solution
{lbs/Gal.}
Solution
Specific
Gravity
Conver-
sion
Factor
7.00 .84 .92
7.50 .90 .95
8.00 .96 .98
8.34 {Water} 1.00 1.00
8.50 1.02 1.01
9.00 1.08 1.04
9.50 1.14 1.06
10.00 1.20 1.10
10.50 1.26 1.12
10.65 {Nitro-
gen 28%}
1.28 1.13
11.00 1.32 1.15
11.50 1.38 1.18
12.00 1.44 1.20
14.00 1.68 1.30
Table 5: Density Conversion Table
Useful Formulas
GPM = GPA x MPH x W*
5940
*W = Row Spacing.....in inches.
GPA = 5940 x GPM {Per Nozzle}
MPH x W*
Let’s assume you are using TeeJet ® XR8006 nozzles
and want to spray at 40 psi pressure. From the nozzle
chart at a 30" spacing, determine the desired speed of
travel.
If the value of 24.86 GPA is not an exact number shown
on the nozzle chart. Interpolation to find an exact figure
in needed. Interpolation is simple once you have an un-
derstanding of how it works {don’t be intimidated}. From
the XR8006 nozzle chart at 30" spacing and 40 psi 24.86
GPA falls between 29.70 GPA at 4 mph and 23.76 GPA
at 5 mph.
Basically, you need to find the percentage that 24.86
GPA is between 23.76 GPA & 29.70 GPA. To do this,
take a factor of the differences.
24.86 - 29.70 = -4.84 = 0.81or 81%
23.76 - 29.70 -5.94
In order to find the value for the mph that is 81% be-
tween 4 mph & 5 mph, take the fraction 0.81 times the
difference in miles per hour.
(0.81) (1 mph) = 0.81 mph
Therefore, the speed of travel needed is:
4 mph + 0.81 = 4.81 mph
From the same example, determine the pressure need-
ed to spray at 5 mph. From the XR8006 chart at 30",
24.86 GPA falls between 25.15 GPA at 45 psi and 23.76
GPA MPH
29.70 at 4
24.86 at
23.76 at 5
-4.84
-5.94
?
Difference
Difference 1.0
Differ-
ence