How often should pesticide application equipment be calibrated?

• A. On a regular basis to detect changes due to wear, corrosion and aging
• B. Only the first time it is used and when a different applicator uses the equipment
• C. On a yearly basis, before it is put away for the season
• D. The first time it is used and when changes are made to the equipment

Answer: (A)

Regular calibration keeps the spray rate accurate as equipment wears and ages. Over time components such as nozzle tips, screens, pumps, hoses, and fittings can change what the system actually delivers. Wear can alter flow and pressure, and small changes add up to either under- or over-application if you don’t check it. By calibrating on a regular basis, you catch drift early, maintain label accuracy, and protect crops and the environment.

Calibrating only the first time, or only yearly, or only after changing equipment, misses the gradual changes that happen with use. The first-time check doesn’t account for wear that occurs during the season, and a yearly check might be too infrequent for many operations. Regular checks—and after any maintenance or component replacement—keep every application consistent.