Smithco Turf Spraying Guide - Manual (Page 24)

mathematical computations would be required.
 To determine an area which is 1/128 of an acre:
On nozzles with 20 inch (51 cm) spacing, measure off a distance of 204 ft. (62
meters). Mark a "START" and a "STOP" line. The rectangle formed by this
distance and the spraying width of one nozzle (20" 51 cm) is equal to 340 square
feet which is equal to 1/128 acre. Therefore, the amount of material applied to
this area by one nozzle in OUNCES is the same amount of material applied to an
acre in GALLONS (GPA).
On nozzles with 10 inch (25 cm) spacing, the measure distance is 408 feet (124 meters).
On nozzles with 30 inch (76 cm) spacing the measured distance is 136 feet (41 meters).
b. CALIBRATING FOR APPLICATION
1. Fill the sprayer tank with water. Run the sprayer, inspect it for leaks and make sure all systems function
properly.
2. Drive the sprayer through the measured distance
discussed above at normal spraying speed, record
the travel time required to cover the measured
distance in seconds with a stopwatch. The carrying
or towing vehicle is to be traveling at the desired
speed when it crosses the start line of the
measured course. Repeat this procedure and
determine the average of the two times.
3. With the sprayer parked, run the sprayer at the
required pressure level. Catch the output of each
nozzle in a container, which is marked or graduated
in Ounces for the same period of time which it took
the sprayer to cover the measured course in step
#2.
4. NOTE : If a Dedicated Spray Vehicle or a sprayer which is powered by a vehicle's PTO/Hydraulic
system is used, it will be necessary to operate the vehicle engine at spraying speed using a hand
throttle.
5. Observe the volume of water in the collection bottle. The number of OUNCES collected in the time it
takes to cover the marked course. Take the average nozzle output by adding the outputs of each
nozzle and then dividing that sum by the number of nozzles.
6. The NUMBER OF OUNCES collected in the time required to cover the SMALL AREA is equal to the
NUMBER OF GALLONS applied per ACRE. For example: if an average of 40 ounces of water are
collected in the time required to cover the 1/128 acre area, the application rate is 40 gallons per acre
(GPA).
AVERAGE OUTPUT (OUNCES) = APPLICATION RATE (GPA)
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