Which data item is required for halocarbon containers but not necessarily for inert gas containers?

• A. Date of inspection
• B. Gross weight of cylinder plus agent
• C. Type of agent
• D. Person performing the inspection

Answer: (B)

The data item about the gross weight of the cylinder plus agent is the key piece that distinguishes halocarbon containers from inert gas containers. For halocarbon systems, knowing the total charged mass (cylinder plus agent) on the cylinder helps verify that the correct amount of agent is present and hasn't leaked or been undercharged. Since halocarbons are stored under pressure as liquids, the exact mass directly reflects how much agent is available for discharge, which is important for performance checks and service records.

Inert gas systems, by contrast, are evaluated primarily by pressure and cylinder volume rather than the total mass of content. The concentration the system can deliver is managed through pressure/volume relationships, not by weighing the cylinder, so the gross weight data item isn’t as critical or routinely required for those containers.

Thus, the data item that halocarbon containers require but inert gas containers do not is the gross weight of the cylinder plus agent. The other items—date of inspection, type of agent, and the person performing the inspection—are standard data elements that appear on the data plate for both types.