Growsafe Spray Equipment Calibration 2 — Questions and Answers
Question 1: How often should boom sprayer nozzles be replaced?
- When output exceeds the 10% wear tolerance or as recommended by the manufacturer — typically after 60-100 hours of use (Correct answer)
- Only when they become visibly blocked
- Only at the start of each new season regardless of condition
- Only when a calibration check reveals over 50% variation
Correct answer: When output exceeds the 10% wear tolerance or as recommended by the manufacturer — typically after 60-100 hours of use
Nozzle replacement should occur when wear is detected through calibration checks or when the manufacturer's recommended service life has been reached. Most sources recommend checking at 60-100 hours of use.
Question 2: What is the purpose of pressure gauges on a boom sprayer?
- To confirm that the spray pressure is within the range required for the nozzle type being used (Correct answer)
- To measure the concentration of product in the tank
- To indicate when the tank is nearly empty
- To monitor the engine load of the tractor during spraying
Correct answer: To confirm that the spray pressure is within the range required for the nozzle type being used
Pressure gauges confirm that operating pressure is within the correct range for the nozzle type. Incorrect pressure changes droplet size and flow rate, affecting both efficacy and drift risk.
Question 3: What does 'boom height' affect in terms of spray pattern quality?
- Boom height determines how well the spray patterns from adjacent nozzles overlap to create uniform coverage (Correct answer)
- Boom height only affects the operator's visibility of the crop
- Boom height determines the pressure at each nozzle
- Boom height is relevant only when spraying into the wind
Correct answer: Boom height determines how well the spray patterns from adjacent nozzles overlap to create uniform coverage
For flat fan nozzles, boom height must be set so that adjacent nozzle patterns overlap sufficiently to create uniform coverage. Too high or too low causes either excessive overlap or bare strips.
Question 4: What is the 'tank mixing order' for preparing a spray solution?
- Half fill with water, add wettable powders or flowables first, then emulsifiable concentrates, top up with water (Correct answer)
- Always add all products at once to the full tank of water
- Add oil-based products first to coat the tank surface before adding water
- Always premix all products in a separate container before adding to the tank
Correct answer: Half fill with water, add wettable powders or flowables first, then emulsifiable concentrates, top up with water
The standard mixing order — half fill, add products in the correct sequence (typically wettable powders before emulsifiable concentrates), then top up — ensures proper dispersion and compatibility.
Question 5: What safety measure must be taken before performing any maintenance on a spray boom?
- Ensure the system is fully depressurised and the tank is empty before opening any fittings (Correct answer)
- Only wear gloves and safety glasses before maintenance
- Flush the system once with clean water and then proceed immediately
- Maintenance may proceed safely with full PPE as long as the engine is switched off
Correct answer: Ensure the system is fully depressurised and the tank is empty before opening any fittings
Spray systems under pressure can release product suddenly when fittings are opened. The system must be fully depressurised and the tank emptied or isolated before any maintenance.
Question 6: What should an operator record after each calibration check?
- The date, nozzle outputs, travel speed, calculated application rate, and any adjustments made (Correct answer)
- Only whether the sprayer passed or failed the calibration check
- Only the final application rate achieved
- Only the tank volume used in the calibration process
Correct answer: The date, nozzle outputs, travel speed, calculated application rate, and any adjustments made
Calibration records provide a history of sprayer performance, support traceability of application rates, and demonstrate due diligence. Detailed records are more useful than simple pass/fail notes.
Growsafe Spray Equipment Calibration 2
How often should boom sprayer nozzles be replaced?