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Operating - Calibration
Calibration
It is outside the scope of this
manual to go through the complete nozzle selection procedure. You
should have been taught the ins and outs of spray quality, nozzle
selection procedures, volumes etc. during your sprayer operators
training, however the following notes should serve as a useful
reminder.
The recommended procedure for
calibrating this, or any other sprayer, is as follows:
1. Read label
Check the label on the chemical
pack (or accompanying leaflet) for recommended volume of application
and spray quality (nozzle type and operating pressure). Decide on
application rate.
2. Calibrate speed
The Frazier chassis unit is fitted
with an electronic speed meter, however, this will only be accurate
if the information programmed into it is correct. Please see the
chassis unit manual for the correct calibration procedure.
The following procedure should be
used to double check the accuracy of the instrument.
a. Carry out a trial run to
establish a forward speed which gives an acceptable level of boom
stability and an appropriate gear and engine speed for the ground and
crop conditions.
b. Carry out a check over a marked
distance of 100 metres, using the speed decided above. Measure the
time taken, in seconds, to cover this distance.
c. Establish the actual forward
speed from the formula: 360 ÷ Time in seconds = speed in km/h
d. Adjust engine speed and repeat
check to get required forward speed.
3. Calculate Nozzle output
a. Measure and record the nozzle
spacing. Frazier sprayers normally have a spacing of 0.5 metres.
b. Calculate and record the output
per nozzle required to achieve the intended volume of application
using the following formula:
Application volume (l/ha) X
Speed (km/hr) X Nozzle spacing (m) ÷ 600 = Nozzle output (l/min)
4. Select and fit nozzles
Refer to nozzle manufacturer's data
charts or cards, or to MAFF lists, and select type and size of nozzle
that will provide the calculated nozzle output and the spray quality
required. Record the recommended spraying pressure for the required output.
5. Check nozzles
a. Fill sprayer with CLEAN water,
start spraying and set pressure to the pressure decided above.
b. Check spray patterns and
alignment visually. Replace any faulty nozzles and re-check.
c. Compare the output of individual
nozzles by use of either a nozzle flow meter or a calibrated
recording jug. Replace nozzles with more than a ± 5% variation
from the average.
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