3
Objective of Calibration
• Determine the volume or weight that application equipment will apply to a known area under a given set of conditions.
4
VOLUME OF PESTICIDE SOLUTION APPLIED DEPENDS
UPON:
• NOZZLES
• PRESSURE
• SPEED
• Spacing of Nozzles
• Viscosity of liquid
• WHY CALIBRATE??
5
1984 Colorado SprayCheck Program
Commercial Applicators
Private Applicators
average initial error 17.5% 25.8%
average corrected error
6.6% 5.5%
under-application 50% 40%
over-application 17% 37%
with 10% range 33% 23%
8
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
9
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
10
EXAMPLE
• GPA = 30
• MPH = 4
• Nozzle spacing = 20
• GPM = 30 GPA x 4 MPH x 20 in 5940
• GPM = 0.40
11
• 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.
12
TeeJet Standard FlatSpray Tips
GPA - 20 inch spacingTip 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
13
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.
15
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
16
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%
17
MAXIMIZING SPRAYER PERFORMANCE
• NOZZLES– Nozzle types
• Flat fan is best for broadcast application of herbicides
Flat fan Even fan
21
BOOM BUSTERSPRAY 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.)
22
Boom Buster (con’t)
– Extra wide spray pattern. – Excellent pattern and distribution. – All models spray chemicals and fertilizers. – All nozzles have standard pipe threads.
23
Boom Buster (con’t)
• USES– Row Crops, Grain and Pastures – State and County Right-of-Ways – Orchards and Vineyards – Forestry and Utility Right-of-
Ways – Lawn and Turf – Roads, Hedge Rows and Fence
Rows
24
MAXIMIZING SPRAYER PERFORMANCE
• Nozzle uniformity– Nozzle types and orifice sizes must be the
same across the boom
25
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
26
MAXIMIZING SPRAYER PERFORMANCE
• Nozzle materials– Stainless steel,
brass and polymer are the most common.
– Stainless steel is probably the best choice
28
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
July 2003
Misapplication Facts
2%8%
24%
33%
33%Equipment
Drift
Tank Mix
WrongFieldOff Label
Source: Farmland Insurance 1996
July 2003
One micron (m) =1/25,000 inch
• Particle drift results by creating smaller drops.
• Spray droplets are measured in microns and expressed as Volume Median Diameter (VMD).
Relationship of Drift to Drop Size
July 2003
Comparison of Micron Sizes for Various Items (approximate)
• 2000 m
• 850 m
• 420 m
• 300 m
• 150 m
• 100 m
#2 Pencil lead
paper clip
staple
toothbrush bristle
sewing thread
human hair
150
34
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
July 2003
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
37
Cutting Droplet Size in HalfResults in Eight Times the Number of
Droplets
500Microns
500Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
250Microns
38
Cutting Droplet Size
in Half
Results in Eight Times the Number of
Droplets
==2 more droplets fill in the sphere
500Microns
500Microns
250Microns
July 2003
Evaporation and Deceleration of Various Size Droplets*
DropletDiameter(microns)
TerminalVelocity(ft/sec)
Final Dropdiameter(microns)
Time toevaporate
(sec)
Decelerationdistance
(in)
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 assumed: 90 F, 36% R.H., 25 psi., 3.75% pesticide solution
July 2003
Low Drift Nozzle Types• Flat-fan(Spraying Systems, Hardi,
Delavan, Lurmark, others)
• Raindrop (Delavan)
• Drift Reduction Flat-fan (Several)
41
Low Drift Nozzle Types, cont:•Turbo Flood (Spraying Systems)
•Turbo Flat-fan (Spraying Systems)•TurboDrop•AI Flat-fan•SprayMaster Ultra•Compact Venturi
July 2003
Nozzle type(all nozzles areSpraying Systemsnozzles)
40 psi @0.2 gpm
40 psi @0.5 gpm
60 psi @0.5 gpm
% spray volumeunder 200microns (0.5gpm @ 40 psi)
XR 80o 270* 370 300 11
XR 110O 224 310 250 22
Turbo Flat-fan 340 450 400 6
Drift Guard110o
330 390 320 11
Flood - 450 410 3
Turbo Flood - 710 650 less than 1
Dropsize Comparisons (Data provided by Spraying Systems Co.)
*Numbers listed are in Microns (Dv.5)
July 2003
Nozzle Dropsize ClassificationSelection based on droplet size:
• Very Fine
• Fine
• Medium
• Coarse
• Very Coarse
• <119 m
• 119-216 m
• 217-353 m
• 354-464 m
• >464 m
Insecticidesand Fungicides
Herbicides Postemergence
Soil Applications of Herbicides
44
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.
46
Air Atomizers
AirJet (Spraying Systems Co., Illinois)
Shear Guard Plus
(Spray-air USA inc., Idaho)
48
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
51
Droplet Speed• At tip:
– all droplets: (43mph)
• 20 inches below tip:– Large droplets: (17mph)– Small droplets: (4.3 mph)
52
Droplet Direction• Large droplets:
– combination of nozzle and travel direction
– e.g. (18 mph) , (6 mph)
• Small droplets:– whichever way the wind is
blowing
54
Droplets in a Grass Droplets in a Grass CanopyCanopy
InterceptionInterception
PenetrationPenetration
Large dropletsLarge droplets Small dropletsSmall droplets
InterceptionInterception
56
Glyphosate on Tame Oats
Volume Median Diameter (µm)
Ave
na
con
tro
l (%
)
30
40
50
60
70
80
90
100
200 300 400 500 600
12 gpa
8 gpa
4 gpa
57
Glyphosate on Oriental Mustard
Volume Median Diameter (µm)
Bra
ssic
a co
ntr
ol (
%)
30
40
50
60
70
80
90
100
200 300 400 500 600
12 gpa
8 gpa
4 gpa
59
Nozzle Air-
Induced 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
64
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
65
MAXIMIZING SPRAYER PERFORMANCE
• Nozzle placement– Need to be placed for proper overlap. Flat
fan nozzles should overlap 30%.
68
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
Top Related