Step 1 - Determine the effective spray width – approximately 80% of the wetted spray width.
Example—if wetted spray width area is 30 feet — 30 feet x 80% = 24 feet would be the effective spray width
Step 2 - Using the effective spray width that was determined in Step 1, find the calibration distance needed to travel from Table 1.
Step 3 - Measure and mark calibration distance obtained from the Table 1 for the corresponding spray width.
Table 1. Calibration distances for corresponding spray widths.
|Effective Swath Width (ft)||Calibration Distance (ft)|
(swath width x spray distance is approximately 3,400 ft 2 total area)
Step 4 - Determine the number of seconds it takes to travel the calibration distance at the speed that you will be spraying. Be sure machinery is traveling at the spraying speed for the full length of the calibration distance. Note engine RPM and gear and seconds needed for travel distance.
Step 5 - With the sprayer parked and operating at same throttle setting/engine R.P.M. as used in step 4:
Collect spray from cluster nozzles or single nozzle outlet for the number of seconds required to travel the calibration distance.
Note: Machine must be operated at same RPM used for calibration run.
Step 6 - Measure the amount of liquid collected in fluid ounces.
Step 7 - Divide the total number of fluid ounces by 10 to obtain gallons per acre applied.
For example: if you collect 140 ounces, the sprayer will apply 14 gallons per acre.
For a boomless sprayer calibration - Ounces collected / 10 = gallons per acre
The LSU AgCenter and the LSU College of Agriculture