CFA Application Equipment and Calibration 2 — Questions and Answers
Question 1: When calibrating a rotary spreader, what does the 'effective spread width' refer to?
- The physical width of the spreader hopper
- The actual width of coverage that achieves the target application rate (Correct answer)
- The distance between the spreader wheels
- The maximum possible throw distance of the material
Correct answer: The actual width of coverage that achieves the target application rate
Effective spread width is the working width that delivers the target rate uniformly, which is typically less than the maximum throw distance.
Question 2: A granular spreader is set to apply 3 lbs per 1,000 sq ft. After calibration, it actually applies 3.6 lbs per 1,000 sq ft. What is the percent error?
- 10%
- 15%
- 20% (Correct answer)
- 25%
Correct answer: 20%
Percent error = ((3.6 - 3.0) / 3.0) x 100 = 20%.
Question 3: Which nozzle type is best suited for applications requiring low drift and good canopy penetration?
- Flat-fan nozzle
- Hollow cone nozzle
- Air-induction (venturi) nozzle (Correct answer)
- Full-cone nozzle
Correct answer: Air-induction (venturi) nozzle
Air-induction nozzles produce large air-filled droplets that resist drift while still providing good coverage.
Question 4: What effect does increasing boom height have on spray pattern overlap from flat-fan nozzles?
- Overlap decreases, causing streaking
- Overlap increases, improving uniformity up to a point (Correct answer)
- Boom height has no effect on overlap
- Overlap remains constant regardless of height
Correct answer: Overlap increases, improving uniformity up to a point
Increasing boom height widens the spray pattern and increases overlap between adjacent nozzles, improving uniformity until excessive height causes drift.
Question 5: During a jug test, you collect 18.5 oz from a nozzle in 30 seconds. The target output is 20 oz per 30 seconds. What action should you take?
- Replace the nozzle immediately
- Accept the output as within 7.5% tolerance (Correct answer)
- Increase system pressure to compensate
- Decrease travel speed to compensate
Correct answer: Accept the output as within 7.5% tolerance
A 7.5% deviation is within the typical +/-10% acceptable tolerance range for nozzle output.
Question 6: What is the primary reason for conducting a spray system pressure check at the boom rather than at the pump?
- Boom pressure is always higher than pump pressure
- Pressure drops occur through hoses, fittings, and filters between pump and boom (Correct answer)
- Pump gauges are typically inaccurate
- Regulations require boom-level measurements only
Correct answer: Pressure drops occur through hoses, fittings, and filters between pump and boom
Pressure losses through plumbing components mean boom pressure is lower than pump pressure, and boom pressure determines actual nozzle output.
Question 7: When calibrating a liquid fertilizer applicator, you travel 200 feet and collect 0.5 gallons from the system. The boom is 20 feet wide. What is the application rate in gallons per acre?
- 54.4 gal/acre (Correct answer)
- 108.9 gal/acre
- 43.6 gal/acre
- 217.8 gal/acre
Correct answer: 54.4 gal/acre
Area covered = (200 ft x 20 ft) / 43,560 = 0.0918 acres; rate = 0.5 / 0.0918 = 54.4 gal/acre.
CFA Application Equipment and Calibration 2
When calibrating a rotary spreader, what does the 'effective spread width' refer to?