Which diagnostic tool is commonly used to evaluate sprinkler coverage and precipitation rate?

• A. Catch-can test to measure distribution and rate
• B. Rain gauge
• C. Soil moisture probe
• D. Pressure regulator

Answer: (A)

A catch-can test is used to evaluate sprinkler coverage and the rate at which water is applied. By placing several shallow cans at different spots under the sprinkler pattern and running the zone for a set time, you can measure how evenly water is distributed and calculate the average precipitation rate (inches per hour). This directly reveals dry spots, overspray, or areas of excessive coverage, which is what you want to know to adjust heads, nozzles, or run times for uniform irrigation.

A rain gauge measures rainfall at a single point, not how water is distributed across an area, so it doesn’t reflect sprinkler performance. A soil moisture probe tells you current soil moisture but not how evenly irrigation waters the landscape. A pressure regulator changes system pressure but doesn’t assess how well the water is being distributed across the zone.