TM 5-3740-218-13&P
(a) Calculate Swath Width (SW). Effective swath width can vary with altitude, speed, type of application, and
wind speed. Determine swath width with a few test runs. LV system applications have an approximate SW
of
150-350 ft at 100-ft altitude; ULV system applications are approximately 100-200 ft at 100-ft altitude.
(b) Formulate Desired Flow Rate. Once the swath width is known, calculate the desired gallons per minute as
follows:
GPM = GPA x MPH x SW
495
where GPA is in gallons, MPH is miles per hour, and SW is in feet.
Example: 1 gallon per acre, air speed of 55 mph, and a swath width of 200 feet: (1 x 55 x 200)/495 = 22.2
gallons per minute.
This figure is now compared with actual gpm, which was computed in operational test. Adjust hydraulic pressure
to bring actual gpm up or down to match desired gpm. For LV systems, this figure must be divided by number of
nozzles (34). Different nozzles can then be selected to match desired gpm.
GPM/NOZ = GPA x MPH x SW
# NOZ x 495
Example: (1 x 55 x 200) = 0.65gpmpernozzle
(34 x 495)
(2) SD System Adjustment. To determine the desired meter setting, you must know the flight speed, the swath
width, the flow rate of the material being used at each meter setting, and the desired application rate in
pounds per acre. Once you know these variables, you can use the following formula to choose a meter
setting:
NOTE
Excessive wind or an increase in flight altitude will have significant effect on swath width
as well as accuracy of application positioning.
Flow Rate (lb/min) = (App Rate (lb/acre) x SW x MPH
495
(a) Meter Settings. After determining required flow rate, select proper meter setting to provide flow rate. If
pesticide being used is Agrisect, refer to table 2-6. For Agrisect, swath width will normally be 55 ft,
assuming
flight altitude of approximately 50 ft and minimal wind factor. If pesticide other than Agrisect is
being used, a
new flow rate table is necessary. Perform the following:
1
Install left and right hopper assemblies on PDU. Place large container under each hopper assembly.
2
Remove slinger assembly from PDU.
