Which measurement represents the calibration area for knapsack sprayers in feet?

Which measurement represents the calibration area for knapsack sprayers in feet?

• A. 16½ ft × 16½ ft
• B. 10 ft × 10 ft
• C. 20 ft × 20 ft
• D. 12 ft × 12 ft

Answer: (A)

Calibrating a knapsack sprayer means spraying a known patch and recording how much chemical is discharged so you can translate that into gallons per acre. The test area is chosen so the conversion to acres is easy. A square with sides of 16.5 feet covers 272.25 square feet, which is exactly 1/160 of an acre (272.25 ÷ 43,560 = 0.00625 acres). That makes the math simple: if you spray V gallons on this area, the application rate is V × 160 gallons per acre. The other options give areas that aren’t neat fractions of an acre, making the gallons-per-acre conversion less straightforward.

Calibrating a knapsack sprayer means spraying a known patch and recording how much chemical is discharged so you can translate that into gallons per acre. The test area is chosen so the conversion to acres is easy. A square with sides of 16.5 feet covers 272.25 square feet, which is exactly 1/160 of an acre (272.25 ÷ 43,560 = 0.00625 acres). That makes the math simple: if you spray V gallons on this area, the application rate is V × 160 gallons per acre. The other options give areas that aren’t neat fractions of an acre, making the gallons-per-acre conversion less straightforward.