SPRAYER
ACCURACY
July 2003
1
2
Objective of Calibration
• Determine the volume or weight that
application equipment will apply to
a known area under a given set of
conditions.
3
VOLUME OF PESTICIDE
SOLUTION APPLIED DEPENDS
UPON:
•
•
•
•
•
NOZZLES
PRESSURE
SPEED
Spacing of Nozzles
Viscosity of liquid
• WHY CALIBRATE??
4
1984 Colorado Spray
Check Program
Comme rcial
Applicators
Priv ate
Applicators
av e rage initial e rror
17.5%
25.8%
av e rage corre cte d
e rror
6.6%
5.5%
unde r-application
50%
40%
ov e r-application
17%
37%
33%
23%
with 10% range
5
TeeJet nozzle examples
6
Hypro Nozzles
7
NOZZLE TIP
DESIGNATIONS
•
•
•
•
•
SPRAYING SYSTEMS CO.
HSS8002E
HSS 80 02 E
HSS = HARDENED STAINLESS STEEL
80 = 80 DEGREE SPRAY ANGLE
02 = 0.2 GALLON PER MINUTE AT 40
PSI
• E = EVEN FLAT FAN PATTERN FOR
BAND APPLICATION
8
HOW TO CHOOSE THE RIGHT
NOZZLE SIZE
• GPM = GPA x MPH x Nozzle spacing in inches
5940
• GPM = Gallons per minute per nozzle
• GPA = Gallons per acre
• MPH = Miles per hour
9
EXAMPLE
• GPA = 30
• MPH = 4
• Nozzle spacing = 20
• GPM = 30 GPA x 4 MPH x 20 in
5940
• GPM = 0.40
10
• Find nozzle capacity in GPM in
manufacture's catalog.
• Desired spraying pressure = 40 psi
• Using Spraying Systems catalog an 8004
nozzle would work the best.
11
TeeJet Standard Flat
Spray Tips
GPA - 20 inch spacing
Tip No.
PSI
GPM
4 mph
6502-SS
30
0.17
12.9
8002-SS
40
0.2
14.9
11002-SS
50
0.23
16.6
6504-SS
30
0.35
26
8004-SS
40
0.4
30
11004-SS
50
0.45
33
6505-SS
30
0.43
32
8005-SS
40
0.5
37
11005-SS
50
0.56
42
12
Rule of Thumb
• An 8004 nozzle will deliver 40 gpa when
used at 3 mph with 40 psi.
• Likewise an 8002 will deliver 20 gpa
under the same conditions.
• An 8001 will deliver 10 gpa.
13
HOW TO CHANGE
SPRAYER OUTPUT
• NOZZLES
– Best for large changes in output
14
HOW TO CHANGE
SPRAYER OUTPUT
• Pressure
– Only feasible within a limited pressure range
– Pressure must be increased by a factor of 4
in order to double the flow
– 10 GPA at 20 PSI
– 20 GPA at 80 PSI
15
HOW TO CHANGE
SPRAYER OUTPUT
• SPEED
– Only feasible within a limited range of
speeds
– Double ground speed will decrease output by
50%
– 1/2 ground speed will increase output by
50%
16
MAXIMIZING SPRAYER
PERFORMANCE
• NOZZLES
– Nozzle types
• Flat fan is best for broadcast application of
herbicides
Flat fan
Even fan
17
MAXIMIZING SPRAYER
PERFORMANCE
18
MAXIMIZING SPRAYER
PERFORMANCE
19
MAXIMIZING SPRAYER
PERFORMANCE
20
BOOM BUSTER
SPRAY NOZZLES THAT WORK WITHOUT BOOMS
• FEATURES
– All nozzles machined from solid stainless
steel. All have replaceable industrial grade nylon
diffusers. (Tests have shown that this nylon will
outlast stainless steel.)
21
Boom Buster (con’t)
–
–
–
–
Extra wide spray pattern.
Excellent pattern and distribution.
All models spray chemicals and fertilizers.
All nozzles have standard pipe threads.
22
Boom Buster (con’t)
• USES
–
–
–
–
Row Crops, Grain and Pastures
State and County Right-of-Ways
Orchards and Vineyards
Forestry and Utility Right-ofWays
– Lawn and Turf
– Roads, Hedge Rows and Fence
Rows
23
MAXIMIZING SPRAYER
PERFORMANCE
• Nozzle uniformity
– Nozzle types and orifice sizes must be the
same across the boom
24
MAXIMIZING SPRAYER
PERFORMANCE
• Nozzle orientation
– Directed straight down toward the ground
and angled 5 to 10 degrees from parallel to
the boom to prevent collision of spray
droplets from adjacent patterns
25
MAXIMIZING SPRAYER
PERFORMANCE
• Nozzle materials
– Stainless steel,
brass and polymer
are the most
common.
– Stainless steel is
probably the best
choice
26
RELATIVE NOZZLE WEAR
27
MAXIMIZING SPRAYER
PERFORMANCE
• Screens and filters
– Use appropriate
screens and filters
• 0.2 GPM or more
use 50 mesh
• Less than 0.2 GPM
use 100 mesh
28
Spray Drift Management
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Misapplication Facts
8%
2%
Equipment
33%
Drift
24%
Tank Mix
33%
Wrong
Field
Off Label
Source: Farmland Insurance 1996
July 2003
Contributions to Drift
23%
13%
26%
38%
July 2003
Nozzle
Applicator
Physical
Other
Relationship of Drift to Drop Size
• Particle drift results by creating
smaller drops.
• Spray droplets are measured in
microns and expressed as Volume
Median Diameter (VMD).
One micron (m) =1/25,000 inch
July 2003
Comparison of Micron Sizes for
Various Items (approximate)
•
•
•
•
•
•
2000 m
850 m
420 m
300 m
150 m
100 m
July 2003
#2 Pencil lead
paper clip
150
staple
toothbrush bristle
sewing thread
human hair
Droplet Size
• Large droplets have less potential to
drift because they:
– Fall more quickly
– Evaporate more slowly
– Are less affected by wind
• Small droplets often result from:
– High spray pressure
– Small nozzle tips
– Wind shear across the nozzles
34
Drift Potential is Influenced
by
• Volume Median Diameter (VMD)
50%
• Droplet Spectrum (Range - big to
small)
% Volume in droplets less than
200 microns in size
July 2003
1/2 of spray volume = smaller droplets
VMD
1/2 of spray volume = larger droplets
36
Cutting Droplet Size in Half
Results in Eight Times the Number of
Droplets
250
Microns
250
Microns
500
Microns
250
Microns
250
Microns
250
250
250
250
Microns Microns Microns Microns
37
Cutting
Droplet Size
in Half
500
Microns
Results in Eight
Times the Number of
Droplets
=
250
Microns
2 more droplets
fill in the sphere 38
Evaporation and Deceleration
of Various Size Droplets*
Droplet
Diameter
(microns)
Terminal
Velocity
(ft/sec)
20
.04
7
0.3
<1
50
.25
17
1.8
3
100
.91
33
7
9
150
1.7
50
16
16
200
2.4
67
29
25
*Conditions
July
2003
Final Drop Time to
diameter evaporate
(microns)
(sec)
Deceleration
distance
(in)
assumed: 90 F, 36% R.H., 25 psi., 3.75% pesticide solution
Low Drift Nozzle Types
• Flat-fan(Spraying Systems, Hardi,
Delavan, Lurmark, others)
• Raindrop (Delavan)
• Drift Reduction Flat-fan (Several)
July 2003
Low Drift Nozzle Types, cont:
•Turbo Flood (Spraying Systems)
•Turbo Flat-fan (Spraying
Systems)
•TurboDrop
•AI Flat-fan
•SprayMaster Ultra
•Compact Venturi
41
Dropsize Comparisons
Nozzle type
(all nozzles are
Spraying Systems
nozzles)
40 psi @
0.2 gpm
(Data provided by Spraying Systems Co.)
40 psi @ 60 psi @ % spray volume
0.5 gpm 0.5 gpm under 200
microns (0.5
gpm @ 40 psi)
370
300
11
XR 80o
270*
XR 110O
224
310
250
22
Turbo Flat-fan
340
450
400
6
Drift Guard
110o
Flood
330
390
320
11
-
450
410
3
-
710
650
less than 1
Turbo Flood
*Numbers listed are in Microns (Dv.5)
July 2003
Nozzle Dropsize Classification
Selection based on droplet size:
•
•
•
•
•
Very Fine
Fine
Medium
Coarse
Very
Coarse
July 2003
•
•
•
•
•
<119 m
119-216 m
217-353 m
354-464 m
>464 m
Insecticides
and Fungicides
Herbicides
Postemergence
Soil Applications
of Herbicides
Air Inclusion

Just air pressure, or both air and
liquid pressure used to atomize
and carry the spray solution to
the target.

Sprayer operator can vary
droplet size independently of
nozzle flow rate.
44
45
Air Atomizers

AirJet
(Spraying
Systems Co.,
Illinois)

Shear
Guard Plus
(Spray-air USA
inc., Idaho)
46
AirJet Atomizer--- Flow rate vs. Droplet
size
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Air Inclusion Technology
"Air Inclusion technology over last five years,
has done more to reduce off target trespass
than any other technology that I am aware of,
past or present. This technology has come to
the market and has been widely adopted
without mandated regulation. It has been a
voluntary effort by manufacturers,
researchers, growers, and retailers to develop
and promote low-drift application practices
which are in the best interest for agriculture."
Thomas M. Wolf, PhD
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Droplet Dynamics
49
TeeJet XR
Hypro TR
Hypro ULD
Air Bubble Jet
TurboDrop
Delavan Ultra
20 psi
40 psi
75 psi
50
Droplet Speed
• At tip:
– all droplets:
(43mph)
• 20 inches below tip:
– Large droplets:
– Small droplets:
(17mph)
(4.3 mph)
51
Droplet Direction
• Large droplets:
– combination of nozzle and travel direction
– e.g. (18 mph)  , (6 mph) 
• Small droplets:
– whichever way the wind is blowing
52
53
Droplets in a Grass
Canopy
Large droplets
Interception
Small droplets
Interception
Penetration
54
If I use lower Water
Volumes, what are my
nozzle choices?
55
Glyphosate on Tame Oats
Avena control (%)
100
90
80
70
60
12 gpa
50
8 gpa
40
4 gpa
30
200
300
400
500
600
Volume Median Diameter (µm)
56
Glyphosate on Oriental Mustard
Brassica control (%)
100
90
80
70
60
12 gpa
50
8 gpa
40
4 gpa
30
200
300
400
500
600
Volume Median Diameter (µm)
57
13.36 GPA
9.09 GPA
4.81GPA
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Nozzle
AirInduced
Optimal Pressure
(psi)
Relative
Droplet size
Minimum
Volume
TeeJet XR
No
20 to 60
Smallest (*)
3
Hypro TR, VP, Albuz AXI
No
20 to 60
*
3
ComboJet ER
No
20 to 60
*
3
Turbo TeeJet
No
15 to 90
**
5
Hypro LD, Albuz ADI
No
30 to 60
**
5
Air Bubble Jet
Yes
40 to 60
***
7
Greenleaf AirMix
Yes
40 to 60
***
7
Hypro Ultra Lo-Drift
Yes
40 to 60
***
7
ComboJet MR
No
40 to 60
***
7
Greenleaf TurboDrop, XL
Yes
60 to 80
****
9
Albuz AVI
Yes
60 to 80
****
9
Spraying Systems AI
Yes
60 to 80
****
9
Lechler ID / Hardi InJet
Yes
60 to 80
****
9
ComboJet DR
No
60 to 80
*****
10
SprayMaster RainDrop
Ultra
Yes
80 to 120
*****
10
59
Is Boom Height
important?
60
Droplet Number
Droplet Size Within Spray
Pattern
61
MAXIMIZING SPRAYER
PERFORMANCE
62
Spray Height Chart
63
MAXIMIZING SPRAYER
PERFORMANCE
• BOOM HEIGHT
– Rule-of-thumb when using 80 degree tips
– Set the boom above the target by whatever
the distance is between nozzles
• If nozzle spacing is 20" then set boom 20" above
target
64
MAXIMIZING SPRAYER
PERFORMANCE
• Nozzle placement
– Need to be placed for proper overlap. Flat
fan nozzles should overlap 30%.
65
Droplet Number
Boom Height and Overlap
30 % Overlap
66
Droplet Number
Boom Height and Overlap
100 % Overlap
67
Strategies to Reduce Drift
• Select nozzle to increase drop size.
• Increase flow rates - higher application
volumes.
• Use lower pressures.
• Use lower spray (boom) heights.
• Avoid adverse weather conditions.
• Consider using buffer zones.
• Consider using new technologies:
– drift reduction nozzles
– drift reduction additives
– shields, electrostatics, air-assist
68
Spraying Accuracy
69
MAXIMIZING SPRAYER
PERFORMANCE
70
University of Wyoming
Cooperative Extension Service
71