What is the required testing method for a wet system?

The required testing method for a wet system is the inspector's test switch. This testing method is crucial because it verifies that the system can effectively deliver water to the appropriate areas and ensures that the alarm system functions correctly when water flows through the pipes. The inspector’s test switch allows for checking the operational integrity of the system under realistic conditions, which is vital for maintaining safety standards.

In wet systems, where water is stored in the piping at all times, the inspector's test switch activates the water flow in a controlled manner to assess the system's response. This test helps verify that alarms are set off, indicating proper operation and ensuring the system is ready to act in an emergency. Other methods, while helpful in their respective capacities, do not fulfill the specific requirements for testing the operational readiness and integrity of a wet fire protection system as comprehensively as the inspector's test switch does.