Sprayers & Calibration

1. Sprayers & Calibration

2. Application Equipment • Select the right equipment. • Set it up correctly. • Use proper operation procedures. • Perform proper maintenance.

3. Refer first to: • The pesticide/chemical label • Spray equipment manual • Extension guidelines

4. Rates and Droplets Size • Nozzle/orifice size, pressure, and fluid characteristics can all affect: • Flow rate (gal./min, gal./acre) • Droplet size (very important for drift minimization)

5. Choosing the Right Nozzle • Choose a nozzle that will provide a uniform pattern for your application site. • Nozzle outputs should not vary more than 10% on a boom. • Flat fan nozzles are adequate for many applications, but check label directions.

6. Choosing the Right Nozzle • Medium to coarse sized droplets can usually provide good coverage and reduce the potential for drift. • But certain pests or situations may require smaller droplets – check the label. • Labels often specify a droplet size and it is therefore a legal requirement.

7. Choosing the Right Nozzle • Avoid extremely large droplet sizes – can result in poor coverage. • Maintain a spray pressure of 30 - 60 pounds per square inch (psi) or whatever is recommended for the nozzle.

8. There must be enough pressure to develop the pattern

9. An XR 8003 tip would give you 0.26 GPM at 30 PSI but the 110o tip produces a very small droplet at that pressure.

10. Flat Fan and Extended Range Flat Fan • Commonly used tip used for many types of applications. • Boom height and nozzle spacing are important in producing uniform spray pattern. • Extended Range (XR) is a modified flat fan for better drop size control over wider variation of pressures. “XR” = Extended Range

11. Air Induction Nozzle • Air induction nozzles create extra large drops for reduced spray drift by adding air. The resulting larger droplet contains small bubbles of air that bursts on contact with the leaf, spreading out the drop contents after contact.

12. Turbo Nozzles • "Turbo" or pre-orifice nozzles, create larger drops with the turbulence chamber, but also maintain a consistent droplet size throughout a wider range of pressures. • Can be combined with air induction technology.

13. Streaking Causes • Boom too low for nozzles to overlap. • Pressure too low to develop the pattern. 20-inch spacing requires 17-19” above target for 50-60% overlap.

14. Nozzle Material • Hardened Stainless Steel • Stainless Steel • Ceramic • Nylon • Brass Nozzle: Wear vs. Cost

15. Pumps Must Provide • Gallons per minute (GPM) required by all nozzles • Tank agitation (6% of tank volume) • Twenty percent (20%) reserve for wear PLUS PLUS

16. Types of Pumps • Roller • Centrifugal • Gear • Turbine • Diaphragm • Piston • They all have advantages and disadvantages. • Roller, piston, and centrifugal are common in agricultural operations.

17. Types of Pumps

18. Strainers Are Essential • Tank opening (16-20 mesh) • In-Line (20-25 mesh) • Nozzle Screen (50-100 mesh)

19. Clean Up • Thoroughly clean inside and out • Rinse with clean water • See if pesticide label recommends something specific like tank cleaners, ammonia, overnight soaking, etc. • Drain and use corrosion/freeze protection for winter

21. Calibration • One of the first keys to calibrating pesticide application equipment is to accurately determine the flow rate or gallons per acre (GPA) of your sprayer.

22. Flow Rate (GPA) depends on: 1. Spray width or nozzle spacing 3. Ground Speed (MPH) 2. Gallons per minute per nozzle

23. Calibration Tools • Flags • Stopwatch • Measuring tape • Calculator • Measuring cup

24. Ounce Method (no calculations) • Calibration distance based on spray width (4080 /nozzle spacing) • Speed (time to travel calibration distance) • Application rate (number of ounces collected for the recorded time) • Adjust and recalibrate

26. Gallons per Acre • The first thing you need to do if not using the ounce calibration method is to determine the gallons per acre (GPA).

27. Gallons per Acre GPM (per nozzle) X 5,940 GPA = MPH X W 5,940 = A constant (same number always used) to convert gallons per minute, miles per hour and inches to gallons per acre. W = nozzle spacing in inches (or spray width of a single or cluster of nozzles) GPM = gallons per minute MPH = miles per hour

28. Speed Calibration • Use the flags and tape to mark a known distance. 100 ft or 200 ft are typical distances. • Lay out the course on the same terrain where the spraying or spreading is to take place. • Use sprayer loaded water (no chemical) with engine throttle setting and gear that will be used for spraying.

29. Speed Calibration • Do not start timing from a standing start. • The equipment should be up to speed when the first marker is passed. • Use a stopwatch to record the time needed to travel the course. • Measure the time more than once to get an average.

30. Speed Calculation Formula 100 ft X 60* 4 mph = 17 seconds X 88* (*60 and 88 are constants in the formula so you will always use those numbers)

31. Ground Speed • Linear relationship • Doubling speed cuts rate (gpa) in half • Cutting speed in half doubles rate

32. Nozzle spacing • Nozzles should be spaced equally. • Record in inches. • Typically – 20” spacing for boom sprayers. • Repair/replace before calibration.

33. Gallons per minute per nozzle Catch nozzle output for one minute to determine gallons per minute Measure nozzle output 34.6 oz = 0.27 gpmgallons per minute

34. Gallons per acre 5,940 X 0.27 = gallons per minute 4 X 20 inches = nozzle spacing miles per hour = 5,940 X 0.27 = 1663 = 20 GPA 4 X 20 = 80 Final Answer = 20 GPA

35. To Increase Rate • Slow down • Use larger nozzle • Decrease nozzle spacing • Increase pressure (can increase drift potential!)

36. To Decrease Rate • Speed up • Use smaller nozzle • Increase nozzle spacing • Decrease pressure

37. Mix and Spray • Need to Know • Gallons per acre • Pesticide rate per acre • Tank capacity or mix amount

38. Amount to Add to Tank • Tank capacity = 200 gallons • Herbicide rate = 1 quart per acre • Application volume equals 20 gallons per acre 200 gallon tank = 10 acres per tank 20 gallons per acre Add 10 quarts per 200 gallon load

39. Calibrating a Pump-Up Sprayer or Pistol Type Spray Gun for GPA • Lay out a calibration plot that is 18.5 ft by 18.5 ft. (this equals about 1/128th acre). • Note how many seconds are required to spray that area uniformly with water. Maintain a comfortable steady pace while keeping the tank pressure uniform.

40. Calibrating a Pump-Up Sprayer or Pistol Type Spray Gun for GPA • Collect the output from the nozzle for the for the number of seconds timed in step 2. • Ounces collected equal gallons per acre. • Repeat at least once and get an average.

41. Calibrating a Pump-Up Sprayer or Pistol Type Spray Gun for Ft2 • Lay out a calibration plot that is 32 ft by 32 ft. (this equals about 1000 ft2 ). • Note how many seconds are required to spray that area uniformly with water. Maintain a comfortable steady pace while keeping the tank pressure uniform.

42. Calibrating a Pump-Up Sprayer or Pistol Type Spray Gun for Ft2 • Collect the output from the nozzle for the for the number of seconds timed in step 2. • Ounces collected equal ounces/1000 sq. ft. • It is a good idea to repeat and get an average.