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OPERATION
36
Sprayer Calibration
The sprayer calibration procedure will ensure
the sprayer pump is set properly. The reel speed
and conveyor dials are adjusted so that the
sprayer pump will only output the required rate for
the application. Perform this procedure at the
beginning of each season and when changing
nozzle tips. This procedure can also be used to
identify tip wear and replacement.
WARNING: Only perform this
procedure when the spray system has
been rinsed clean. Use only clean
water to fill the tank and perform the
procedure. To reduce the risk of chemical
contamination, always wear the same
protective equipment and take the same
precautions that are required when handling
chemicals and preparing to do an application.
Make several copies of this page. Use a
copy each time you perform a sprayer calibration
and include it in your records. Use the empty
space for calculations and notes. You will need a
calculator, stopwatch, cleaning brush, measuring
container, and one new tip with a new screen.
1. Record the following information.
2. Check windrower speed.
Perform this check to verify the DICKEY-john
Radar velocity is sensor is accurate in the field.
The sprayer speed should be calibrated in the field
when the tank is ½ to ¾ full of water. Record the
time it takes and the distance in the blanks below.
If you are confident the Radar sensor is accurate,
record the desired speed in the blank (C) and
proceed to the next step.
IMPORTANT: The tractor must be traveling at
the desired speed at the starting point before
timing begins.
Calculate the speed or use the chart below to
match the time it takes to travel a specific distance
over your field with the true ground speed.
USGPA
inches
Recommended
Application Rate (A)
Nozzle Spacing (B)
(from chemical manufacturer’s label)
(all nozzles must be identical)
Nozzle Manufacturer
Nozzle Type
Date
feet
seconds
mph
Calculate the true ground speed using the
following equation.
Distance Traveled
Time Taken
True Ground
Speed (C)
88
x
(seconds)
Time
60
x
(feet)
Distance
(mph)
Speed
=
100 Feet
200 Feet
300 Feet
23
45
68
20
39
58
17
34
51
15
30
45
23
27
41
-
23
34
-
19
29
-
18
27
-
17
26
-
15
23
9.0
3.0
3.5
4.0
4.5
5.0
6.0
7.0
8.0
Time required in SECONDS to Travel
a Distance of:
Speed in mph
(Miles per Hour)
7.5