Master Manufacturing 40/60 Gallon 3-point Sprayer - Manual (Page 3)

recommendations of the pump instructions for preventing internal pump corrosion and protection against the
rotor and rollers gumming and sticking during storage.
Boom Operation
The spray nozzles used in the boom are marked with the capacity in gallon per minute of water at a pressure of
40 psi. A 3 tip has a capacity of .3 gpm at 40 psi. A 5 has a capacity of .5 gpm at 40 psi. etc.
The spray width coverage of the nozzle will vary according to the pressure, and nozzle height. The wide angle
flat spray pattern increases as the pressure is increased.
The amount of material applied by the nozzle is changed by variations in spraying speed, different capacity
nozzles, different nozzle spray width and spraying pressures. Other factors such as a heavier or lighter (specific
gravity) spraying solution, a change in the chemical-water concentration ratio, worn tip, a worn pump, wheel
slippage, a pressure drop from the gauge to the boom, and a pressure gauge variation or malfunction can also
cause variations in the rate of application. Uneven coverage can result from a clogged nozzle and a straining
screen.
The spraying pressure is usually more in relation to the type of application and the type of tip used than to the
rate of application. Since nozzle flow rate is almost proportional to the square root of pressure, it would take
four times the amount of range from 10 to 40 psi. The rate of application can be changed somewhat by
changing pressure but a considerable change is achieved by using a different capacity nozzle or (if possible) by
changing the spraying ground speed.
Dividing the spraying width of the boom in feet into 1000 determines the travel distance required to cover 1000
sq. ft. For example, an 80” spray width will cover 1000 sq. ft. in 150 ft. of travel. Periodic calibration checks at
the spraying speed and pressure assure correct application rates. The number of gallons required to refill the
tank after spraying (starting with a full tank) over a test distance is the application rate for the area of the test
distance.
Multiplying the application rate for the 1000 sq. ft. by 43.56 will determine the application rate per acre or
dividing the rate per acre by 43.56 will determine the rate per 10000 sq. ft. If unknown, spraying speed can be
determined by measuring the distance travelled in one minute. Every 88 ft. of travel is equal to 1 mph of speed.
For instance, a distance of 308 ft. in one minute divided by 88 equals 3.5 mph.
A calibration check can also be made with the unit standing still and the boom spraying at the operation RPM
and pressure. Catching the output of the one nozzle for the time it would take to travel the test distance and
multiplying by the number of nozzles on the boom will yield the application rate. Water weighs 8.34 lbs. per
gallon. Spraying solutions heavier than water will cause a reduction in nozzle output, while solutions lighter
than water will increase the nozzle output.