What is the primary purpose of calibration in spraying at the field speed and pressure used?

• A. To determine the water tank capacity
• B. To determine the gallons per acre (GPA) to apply
• C. To measure nozzle wear rate
• D. To optimize fuel efficiency per acre

Answer: (B)

Calibration at the field speed and pressure used is about knowing exactly how much chemical is applied per acre. By measuring the nozzle output under those conditions and using the swath width and travel speed, you calculate gallons per acre. This lets you match the spray to the label rate, ensuring effective coverage and minimizing drift or over-application. The other options aren’t the primary goal: water tank capacity is about how much you can hold, not how much you apply per area; nozzle wear rate concerns future accuracy but isn’t the immediate purpose of calibrating at the current speed and pressure; fuel efficiency per acre depends on many factors beyond the actual application rate.