- Practice a nozzle and movement technique so each trigger pull treats one square foot.
- Attach the gun to a backpack sprayer, then pressurize and set the calibration ring to a fixed value.
- Pull the trigger 20 times into a precise measuring container. This equates to the volume for treating 20 square feet.
If you’re utilizing pesticides on a per 1000 square foot basis this would equal 1/50 of 1000 square feet. For example, if 4 fluid ounces of spray were collected in 20 trigger pulls, this equals 4 fluid ounces per 20 square feet, or 200 fluid ounces per 1000 square feet. Convert to gallons by dividing 128 [ounces per gallon] into 200, which equals 1.56 gallons per 1000 square feet (or 68 gallons per acre). This provides a calibration setting to add the appropriate amount of pesticide per gallon of water in the backpack sprayer.