Power sprayers:

Power sprayers must be calibrated to ensure the correct amount of pesticide is applied, as application rates can vary due to wear, nozzle changes, or pressure adjustments. TheGeneral Pest Management: Guide for Commercial Applicators - Category 7A(Chapter 5: Pesticide Application) stresses that applicators should check calibration regularly to ensure accuracy, especially for Category 7A applications. Option A is incorrect because factory calibration does not account for field conditions or equipment changes. Option C (annual calibration) is a good practice but not a strict requirement; the need for calibration depends on usage and equipment condition.