GENERAL INFORMATION:
WHEN TO SPRAY:
Results will be best when wind speed is low, temperature low and relative humidity high. An ideal
time is at sunup when these conditions are most likely to apply.
APPLICATION RATE:
The application rate depends on the following.
•
Speed of travel - increasing speed reduces application rate and vice versa.
•
Operating pressure - increasing pressure increases the application rate and reducing pressure
decreases the rate.
•
Nozzle size - increasing the nozzle size increases the application rate.
𝐴𝑝𝑝𝑙𝑖𝑐𝑎𝑡𝑖𝑜𝑛 𝑅𝑎𝑡𝑒 (𝐿 𝐻𝑎
⁄
) =
600 × 𝑁𝑜𝑧𝑧𝑙𝑒 𝑂𝑢𝑡𝑝𝑢𝑡 (𝑙 𝑚𝑖𝑛
⁄
)
𝑆𝑝𝑒𝑒𝑑 (𝑘𝑚 ℎ𝑟
⁄
) × 𝑁𝑜𝑧𝑧𝑙𝑒 𝑆𝑝𝑎𝑐𝑖𝑛𝑔 (𝑚)
GROUND SPEED:
The speedometer on many vehicles may not be sufficiently accurate at the slow speeds used when
spraying. If in doubt it should be checked by the following method.
Fill the sprayer with water to simulate the normal spraying weight of the vehicle. Ensure that the
tyres are correctly inflated.
Measure and mark 100 metres. Approach the starting mark at the required spraying speed and
accurately measure the time in seconds to reach the finishing mark. The ground speed can then be
calculated as follows.
𝑆𝑝𝑒𝑒𝑑 (𝑘𝑚 ℎ𝑟
⁄ ) =
360
𝑡𝑖𝑚𝑒 𝑖𝑛 𝑠𝑒𝑐𝑜𝑛𝑑𝑠 𝑓𝑜𝑟 100𝑚
BOOM TEST (NOZZLE OUTPUT):
1.
Partly fill the sprayer tank with water and mark the level or refer to the sight gauge.
2.
Run the sprayer for several minutes with all boom’s sections operating and measure the time
carefully.
3.
Refill the sprayer tank to the mark using a measuring jug and record the amount added.
4.
The average output for one nozzle in litres per minute can be calculated as follows.
𝑁𝑜𝑧𝑧𝑙𝑒 𝑂𝑢𝑡𝑝𝑢𝑡 (𝑙 𝑚𝑖𝑛
⁄
) =
𝐿𝑖𝑡𝑟𝑒𝑠 𝑈𝑠𝑒𝑑
𝑁𝑜. 𝑁𝑜𝑧𝑧𝑙𝑒𝑠 × 𝑁𝑜. 𝑀𝑖𝑛𝑢𝑡𝑒𝑠
The output calculated should agree with the flow rate shown in the Spray Nozzle Selection Chart,
for the nozzles fitted.
5.
If the nozzle output is lower than shown in the table the pressure may be increased and the test
repeated or, if more than shown, the pressure may be reduced. (If optional pressure regulator is
fitted)
Calibration
