How are design concentrations verified during maintenance?

• A. By visual inspection only.
• B. By functional testing, measurements, and rechecking calculations against current room conditions.
• C. By replacing detectors.
• D. By consulting operation manuals only.

Answer: (B)

Design concentration verification during maintenance relies on a complete, reality-based assessment that combines functional testing, actual concentration measurements, and rechecking calculations against current room conditions. Functional testing ensures the release system operates as intended, including the sequence and timing needed to deliver the agent to the space. Measurements provide real data on the actual agent concentration achieved in the protected space, taken at representative locations and over the required duration, to confirm the target level is reached. Rechecking calculations updates the design concentration based on the present room data—volume, leakage paths, openings, occupancy, and any changes to the space—as conditions can differ from when the system was first designed. Visual inspection alone cannot confirm that the proper concentration will be achieved, and simply replacing detectors or consulting manuals does not verify performance under actual conditions.