Calibration, Mixing and Application Equipment
This domain tests calibration, mixing, and application equipment. The exam expects you to calculate spray volume, check nozzle output, set pressure and speed, and recognise worn or wrong equipment.
Core rules
- Calibrate before each season and whenever you change nozzle, pressure, speed, or product. Use clean water.
- Spray volume in L/ha = (nozzle output in L/min × 600) ÷ (speed in km/h × swath in m). Measure output from several nozzles; replace those more than 10% above or below the average.
- Area covered per tank = tank volume ÷ spray volume. Match the area to the product rate so the tank contains the correct amount.
- Keep pressure within the nozzle's rated range, maintain speed, and avoid partial overlaps. Triple-rinse and clean filters and nozzles after use.
Worked example
A knapsack nozzle delivers 1.2 L/min. You walk at 4 km/h with a 1.0 m swath. Spray volume = (1.2 × 600) ÷ (4 × 1.0) = 180 L/ha. A 15 L tank covers 15 ÷ 180 = 0.0833 ha, or 833 m². If the label rate is 2 L product/ha, put 2 × 0.0833 = 0.167 L (167 mL) in the tank. The reasoning ties output, speed, and swath to a measured area, not a guess.
Traps
Calibrating with the pesticide in the tank; ignoring pressure changes; using a worn nozzle; and calculating for 1 ha when the tank covers only a fraction.