Smithco Turf Spraying Guide - Manual (Page 22)

b . CALIBRATION STEPS USING THE NOZZLE CHART METHOD
Determine "HOW" your sprayer is to be calibrated from the list of variable factors available (above).
1. NOZZLE TYPE Teejet, Raindrop, Turbo Flood ?
2. SPACING 10" (25 cm) or 20 (51 cm) or 30" (76 cm).
3. EXPRESSION OF APPLICATION RATE G.P.A. or G.P.T. or L.P.H.
The answers to these three questions will direct you to the appropriate nozzle chart for your
application among the charts on the pages in the back of this guide. The correct nozzle chart MUST
be used.
c
. DETERMINE THE DESIRED APPLICATION RATE.
This is determined from the information on chemical labels or other technical information available
from a variety of sources.
d
. DETERMINE AN ACCEPTABLE GROUND SPEED
Conditions over which the sprayer will operate generally dictate the appropriate ground speed.
Within the limits of practicality and efficiency, spraying should generally be done at the lowest
possible speed. This increases operator safety and contributes to more precise application of
chemicals. For example, golf greens and tees and hill areas would generally be sprayed in the range
of 2 1/2 to 3 1/2 Miles per hour (4-6 kph). Larger, open and more level areas such as golf fairways
and open park or school grounds would be sprayed at 4 1/2 to 6 mph (7-10 kph). The best guideline
is the fastest speed, which is “safe and comfortable for the piece of equipment.” Often, operators
can withstand more punishment than the sprayer.
The vehicle which carries or tows the sprayer should be equipped with a precise low-speed
speedometer. If it is not, exact ground speed at a given engine speed must be determined by timing
the travel of the sprayer over a measured course.
e . DETERMINE NOZZLE SIZE
Now refer to the appropriate nozzle chart in this guide for your nozzle TYPE (the type of nozzle you
have or the type you wish to use), nozzle SPACING and CALIBRATION TYPE (GPM, GPT or LPH).
You will note from the chart that application rates from any given nozzle decrease as the ground
speed increases. In other words, the faster you drive, the less material you are applying.
Application rates are shown in the columns to the right of the charts. Once the desired application
rate is decided upon, it should be located, as nearly as possible in one of these columns on the
appropriate chart for your operation. It could well be that the approximate rate desired would be
obtained from the nozzles already installed in the boom. If this is not possible, then nozzles will need
to be changed.
IMPORTANT NOTE: When selecting a new nozzle size refer to the Discharge Rate Column" on the
nozzle charts. The Discharge Rate (GPM or LPM) multiplied by the number of nozzles should not
exceed 75% of the actual discharge volume of the sprayer pump. (i.e., if you need to use nozzles
which discharge 0.8 gallons per minute [3.0 Liters per minute], and the spray boom is equipped with
12 nozzles, the sprayer pump would have to produce an actual discharge volume of 13 GPM ~49
LPM] in order to properly supply these nozzles.) If the collective volume of the spray boom nozzles
exceeds the actual discharge volume of the pump, inadequate pressure and poor nozzle distribution
patterns may result.
Once nozzle type and size have been determined, those nozzles are installed in the sprayer boom.
Nozzles could be expected to be replaced after 15-20 hours of actual sprayer operation if made of
softer materials. After nozzles are installed, make trial application of water over a known area to
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