1. SPRAYER ACCURACY
July 2003

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 Spray Check Program

6. TeeJet nozzle examples

7. Hypro Nozzles

8. NOZZLE TIP DESIGNATIONS SPRAYING SYSTEMS CO.
HSS8002E
HSS 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
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
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 Flat Spray Tips GPA - 20 inch spacing

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.

14. HOW TO CHANGE SPRAYER OUTPUT
NOZZLES
Best for large changes in output

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

18. MAXIMIZING SPRAYER PERFORMANCE

19. MAXIMIZING SPRAYER PERFORMANCE

20. MAXIMIZING SPRAYER PERFORMANCE

21. 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.)

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

27. RELATIVE NOZZLE WEAR

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

29. Spray Drift Management

30. Misapplication Facts
Source: Farmland Insurance 1996
July 2003 3

31. Contributions to Drift
July 2003 3

32. 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

33. Comparison of Micron Sizes for Various Items (approximate)
#2 Pencil lead
paper clip
staple
toothbrush bristle
sewing thread
human hair
150
July 2003

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

35. 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

36. VMD 1/2 of spray volume = smaller droplets
1/2 of spray volume = larger droplets

37. Cutting Droplet Size in Half Results in Eight Times the Number of Droplets
250
Microns
250
Microns
500
Microns
250
Microns
250
Microns
250
Microns
250
Microns
250
Microns
250
Microns

38. Cutting Droplet Size in Half
Results in Eight Times the Number of Droplets
Cutting Droplet Size in Half =
500
Microns
250
Microns
2 more droplets fill in the sphere

39. Evaporation and Deceleration of Various Size Droplets*
Terminal
Final Drop
Time to
Deceleration
Diameter
Velocity
diameter
evaporate
distance
(microns)
(ft/sec)
(microns)
(sec)
(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

40. Low Drift Nozzle Types
Flat-fan(Spraying Systems, Hardi, Delavan, Lurmark, others)
Raindrop (Delavan)
Drift Reduction Flat-fan (Several)
July 2003

41. Low Drift Nozzle Types, cont:
Turbo Flood (Spraying Systems)
Turbo Flat-fan (Spraying Systems)
TurboDrop
AI Flat-fan
SprayMaster Ultra
Compact Venturi

42. Dropsize Comparisons (Data provided by Spraying Systems Co.)
Could we add a chart using Erdal’s or Green Leaf’s data on the Turbo Drop comparison to conventional?
*Numbers listed are in Microns (Dv.5)
July 2003

43. Nozzle Dropsize Classification
Selection based on droplet size:
Very Fine
Fine
Medium
Coarse
Very Coarse
<119 m m m m
>464 m
Insecticides
and Fungicides
Herbicides
Postemergence
Soil Applications
of Herbicides
July 2003

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 Shear Guard Plus (Spraying Systems Co., Illinois)
(Spray-air USA inc., Idaho)

47. AirJet Atomizer--- Flow rate vs. Droplet size

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

49. Droplet Dynamics

50. 20 psi 40 psi 75 psi TeeJet XR Hypro TR Hypro ULD Air Bubble Jet
TurboDrop
Delavan Ultra
20 psi
40 psi
75 psi

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 Canopy
Large droplets
Small droplets
Interception
Interception
Penetration

55. If I use lower Water Volumes, what are my nozzle choices?

56. Glyphosate on Tame Oats
100 90
4 gpa 80 70
Avena control (%) 60
12 gpa 50
8 gpa 40 30
200
300
400
500
600
Volume Median Diameter (µm)

57. Glyphosate on Oriental Mustard
100
4 gpa 90 80 70
Brassica control (%) 60
12 gpa 50
8 gpa 40 30
200
300
400
500
600
Volume Median Diameter (µm)

58. 13.36 GPA GPA GPA

60. Is Boom Height important?

61. Droplet Size Within Spray Pattern
Droplet Number

62. MAXIMIZING SPRAYER PERFORMANCE

63. Spray Height Chart
Use this slide to demonstrate where the numbers from the previous slide came from, and to point out that the Spray Parts Guide contains charts like this.

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%.

66. Boom Height and Overlap
Droplet Number
30 % Overlap

67. Boom Height and Overlap
Droplet Number
100 % Overlap

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

69. Spraying Accuracy

70. MAXIMIZING SPRAYER PERFORMANCE

71. Cooperative Extension Service
University of Wyoming
Cooperative Extension Service