During installation or servicing, an operator must ensure that the air system is which of the following?

The correct answer highlights the importance of continuous monitoring for leaks in the air system during installation or servicing. Maintaining a leak-free environment is crucial for the safety and efficiency of the sprinkler system. If there are leaks, it can lead to a loss of pressure in the system, which may affect its performance and reliability. Continuous monitoring allows operators to quickly identify any problems and address them before they escalate, thereby ensuring the system operates effectively and reduces the risk of malfunctions.

In the context of system operation, the other options might seem relevant but do not align with best practices. Pressurizing the system above normal operating limits can pose safety risks and damage components. Disconnecting from the power supply might be appropriate in some scenarios, but it does not directly relate to ensuring the integrity of the air system itself. Maintaining a constant pressure is generally important, but without continuous monitoring for leaks, maintaining that pressure cannot be assured. Thus, consistent leakage monitoring is the best practice to ensure the system's reliability and functionality during installation or servicing.