11
Nozzle tip calibration
The output of individual nozzles must be within
5
per cent of the average nozzle output to provide
an even volume over the width of the spray swath.
Nozzles with outputs either above or below this value
must be replaced.
•
With the spayer operating at the recommended
spraying pressure (275 kPa), collect, measure and
record the output from each nozzle on the boom for
one minute. Note: if nozzle strainers are equipped
with ball-check valves, increase pressure by 35 kPa.
•
Calculate the average output.
•
Replace nozzles with output 5 per cent greater
than average. Clean and recheck nozzles with
output 5 per cent less than average.
Ground speed determination
Actual ground speed can be confirmed by noting the
time it takes to travel a measured distance. The
following ground speed chart is based on the time
required to travel 800 metres.
Speed
Travel time for 800 m
(
km/h)
(
min:sec)
7
6:48
8
6:00
9
5:20
10
4:48
11
4:22
12
4:00
Sprayer Calibration – Example
L/acre
Step 1: Determine the number of acres to spray
using your field records.
Example: 30 acres
Step 2: Know the sprayer tank capacity, which is
marked on sprayer tank.
Example: 2,000 litres
Step 3: Determine spray volume needed per acre,
which can be obtained from the pesticide label or this
publication.
Example: 40 litres per acre recommended
Step 4: Select nozzles for 40 litres per acre from the
manufacturer’s chart or the sample nozzle chart in
this publication.
Example: Nozzle No. 11002 at 275 kPa and 9 km/h =
40
L/acre
Step 5: Check nozzle output. See nozzle tip
calibration.
Example: Nozzle flow between 0.71 to 0.79 litres per minute
per nozzle is okay
Step 6: Calculate total spray solution needed by
multiplying number of acres
x
litres per acre.
Example: 30 acres x 40 litres per acre = 1,200 litres
Step 7: Calculate the total amount of pesticide needed
from the pesticide label or this publication (multiply
litres of pesticide per acre
x
number of acres to spray).
Example: 0.60 L/acre x 30 acres = 18 L of pesticide and
1,182
L of water in sprayer tank
Step 8: Set sprayer to travel at desired speed.
See Step 4 (example) and nozzle chart.
Example: Required speed = 9 km/h (36 seconds to travel
Standard Benchmarks
Application volume: 40 litres per acre (L/acre) = 100 litres
per hectare (L/ha) = 8.8 Imperial
gallons per acre
Spraying pressure: 275 kilopascals (kPa) =
40
pounds per square inch (psi)
Speed for spraying: 9 kilometres per hour (km/h) =
5.4
miles per hour (mph)
Nozzle spacing on spray boom: 0.5 m = 20 inches (in.)
Height above target for 80° and 110°
Nozzle tips: 45 centimetres (cm) = 18 inches (in.)
Nozzle tips: 8002 or 11002
Note: A standard nozzle puts out 0.75 litres per
minute at 275 kPa. At 9 km/h, these nozzles apply
40
L/acre of spray.
Metric equivalents
1
acre
= 0.405 hectare
2.471
acre = 1 hectare
6.9
kPa
= 1 psi
1.6
km/h = 1 mph
2.54
cm
= 1 in
1
litre/acre = 2.5 litre/ha