Filter
Top Products
Calibration Method #2
This method calibrates the sprayer, but does not
check for worn nozzles.
This method gives you the distance driven to cover
1/128 acre (because there are 128 ounces per gallon).
The time required to drive that distance is measured
first and then volume of spray in ounces caught in the
time you measured is your application rate in gallons
per acre. From the chart below, determine the dis-
tance to drive in the field (three runs are suggested) to
obtain your average time in seconds.
1. Determine your nozzle size, spacing (20” is stan-
dard on all Locke Turf Booms) and pressure to
achieve your desired rate from the flow charts on
the following pages.
2. Measure the nozzle spacing on your boom and
determine the distance to dive to calibrate your
sprayer.
3. Mark off the distance with two markers and time
how many seconds it takes to drive this distance
at the desired spraying speed. Make sure you are
at spraying speed when you cross both marks.
Two or more runs are suggested with the sprayer
half full.
4. With the sprayer filled with water (no chemical
added). Park in an appropriate area with the
booms unfolded. Prepare to collect samples at
the individual nozzles. Turn on the pump and run
it at the operation pressure. If applicable, cor-
rectly set the solenoid throttling valves. Refer to
Calibrating the Throttling Valves in “General Op-
erations” section starting on page 21. Flip on the
boom section switch on the control box and catch
the water being sprayed out of the nozzle you are
calibrating.
5. Measure the volume of the sample in ounces over
the time it took to travel the distance in step #3.
The number of ounces caught is the exact number
of gallons per acre you will apply with that nozzle.
Distance for Each Nozzle to Spray 1/128 Acre
Average Average
Nozzle Distance Nozzle Distance
Spacing (Feet) Spacing (Feet)
(Inches) (Inches)
6 681 22 186
8 510 24 170
10 408 30 136
12 340 36 113
14 292 38 107
15 272 40 102
16 255 42 97
18 227 48 85
20 204
Calibration Method #3
To double check the accuracy of your sprayer, the fol-
lowing instructions provide another method of calibra-
tion:
1. Measure 200 feet and determine the number of
seconds required to travel this distance under field
conditions with implements in working condition.
2. Place graduated container or pre-weighed con-
tainer under one nozzle and catch the discharge for
1 minute. Divide 128 into the number of fluid
ounces caught. 128 fluid ounces equals one gal-
lon. EXAMPLE: 1 nozzle every 20” (standard for
all turf booms).
EXAMPLE:
Gallons per acre = 5940 x Gallon per minute
Nozzle spacing in inches x
Miles per Hour
GPA = 5940 x .50
20 x 5
GPA = 2970
100
GPA = 29.7
The above information will assure you of a check for
accurate application in the event there is an error in the
gauge nozzle spacing, nozzle height, vehicle speed or
nozzle wear.
Useful Formulas & Conversions
GPM TO OPM CONVERSIONS
GPM (GALLONS PER MINUTE) X 128 = OPM (OUNCES PER MINUTE)
EXAMPLE: 0.5 GPM X 128 = 64 OPM
OPM O GPM CONVERSIONS
OPM (OUNCES PER MINUTE) ÷ 128 = GPM (GALLONS PER MINUTE)
EXAMPLE: 32 OPM ÷ 128 = 0.25 GPM
AREA COVERAGE
A 20’ WIDE BOOM (STANDARD FOR TURF SPRAYERS) COVER
2.4 ACRES PER 1 MILE OF TRAVEL
GALLONS PER HOUR TO GALLONS PER MINUTE CONVERSION:
GPM = GPA x MPH x W*
5940
W* = NOZZLE SPACING IN INCHES
GALLONS PER MIINUTE TO GALLONS PER HOUR CONVERSION
GPA = 5940 x GPM (PER NOZZLE)
MPH x W*
W* = NOZZLE SPACING IN INCHES
17