Rapid Spray Spot Ranger Operators Handbook
Rapid Spray Equipment by Rapid Spray
REVA 11/05/2018
7
CALIBRATION GUIDELINES FOR SPRAY GUNS
Non-calibrated spray nozzles can lead to inaccurate application rates, spray patterns and
droplet size, which can reduce herbicide effectiveness. The first and most important step in
sprayer calibration is to choose the correct nozzle type and size for your application.
Nozzles and Pressures for Different Spray Volumes
SPRAY VOLUME
NOZZLE
DIAMETER
OUTPUT
PRESSURE
PSI
(L/ha)
(mm)
(L/min)
(kpa)
1000 - 2000
D4
1.6
2.5
400
57
1500 - 3000
D5
2.0
3.8
500
71
2000 - 4000
D6
2.4
5.5
600
85
3000 - 6000
D7
2.8
7.8
700
100
4000 - 8000
D8
3.2
8.6
800
114
Prior to spraying, select a bush to spray and decide what shape the weed can be
categorized as (either dome or cylindrical). Spray that bush normally to achieve good
coverage to the point of run-off. Time how long it took you to spray. Repeat this process
spraying into a bucket. Measure the spray volume and compare this with the recommended
spray and water rate using the tables attached.