What is the primary use of a catch can test in drip irrigation?

• A. To verify the application rate along the emitter grid.
• B. To measure soil moisture.
• C. To clean the emitters.
• D. To test the backflow.

Answer: (A)

The catch can test is used to verify the actual application rate across the emitter grid to ensure water is being distributed evenly. By placing several small catch cans at representative spots in the watered area and running the system for a set time, you collect the water output from different points. Measuring the volumes in the cans and converting that data to an application rate shows whether every part of the grid is receiving roughly the same amount of water. If the results are skewed, you can diagnose issues like emitter flow variation, pressure differences, long header runs, or clogging and make adjustments to bring the distribution back toward the target rate. It isn’t used to measure soil moisture, clean emitters, or test backflow, which involve different procedures and equipment.