Sprayer 1/128-Acre Calibration
USDA Extension 1/128-acre method: boom width determines travel distance, ounces collected per nozzle equals GPA.
Example
You enter
- Boom width (ft) 20
- Ounces collected per nozzle (over 1/128 acre) 20
- Time to travel the distance (s) 2.9
- Target application rate (GPA; optional) 20
You get
- Travel distance for 1/128 acre (ft) 17.0
- Application rate (GPA) 20
- Ground speed (mph) 4
Details, formula, and sources
Speed adjustment closes to a target rate.
travel_distance_ft = (43560 / 128) / boom_width_ft = 340.3125 / boom_width_ft. gpa_actual = oz_per_nozzle (1/128-acre identity: 128 fl oz per gallon).
USDA Cooperative Extension Service public method. Pesticide label rates govern application.
extension.org and land-grant university extension offices.
Estimate. AHJ and licensed professional govern.
Field names used by the API: boom_width_ft, oz_per_nozzle, time_s, target_gpa, travel_distance_ft, gpa_actual, ground_speed_mph
- 1/128-acre identity 128 fl oz per gallon -> oz collected per nozzle = GPA when measured over 1/128 acreUSDA Extension calibration method
- Adjustment threshold 5% deviation from target triggers a suggested-speed correctionengineering practice