IA Sprinkler & Emitter Technology 2

Question 1

What is 'head-to-head spacing' in sprinkler design?

Accepted Answer

Spacing where one head's throw distance equals the spacing between heads

Answer

Head-to-head spacing means the throw radius of each sprinkler reaches the adjacent head, ensuring 100% overlap and uniform coverage.

Question 2

Which sprinkler nozzle type produces the lowest precipitation rate and is most appropriate for clay soils?

Accepted Answer

Rotary nozzle (e.g., MP Rotator)

Answer

Rotary nozzles like the MP Rotator apply water at very low rates (0.4–0.5 in/hr), well suited to clay soils with low infiltration rates.

Question 3

What is the purpose of a check valve built into a sprinkler head?

Accepted Answer

To prevent low-head drainage after the system shuts off

Answer

Integral check valves prevent water from draining out of low-lying heads after irrigation, which wastes water and causes wet spots.

Question 4

A drip system emitter rated at 1.0 GPH operates for 2 hours. How much water has been applied?

Accepted Answer

2.0 gallons

Answer

Volume = flow rate × time = 1.0 GPH × 2 hours = 2.0 gallons per emitter.

Question 5

In a matched precipitation rate (MPR) sprinkler system, what is adjusted to ensure equal precipitation regardless of arc?

Accepted Answer

Nozzle flow rate

Answer

MPR nozzles adjust flow rate proportionally to the arc (e.g., a 90° head uses ¼ the flow of a 360° head) so all heads apply the same depth per hour.

IA - Irrigation Association Certification Practice Test