What alarm activates when the main supply reaches an average day supply in a bulk cryogenic system?

In a bulk cryogenic system, the master alarm serves a crucial role in monitoring the overall system's performance and liquid supply levels. When the main supply approaches an average day supply, this alarm is designed to alert operators of the current status, indicating that attention may be needed to ensure sufficient supply for medical gases.

The master alarm is essential for the timely response required in such systems, as it consolidates multiple alerts into one central system, helping maintenance teams prevent potential failures. This proactive notification mechanism ensures that any necessary actions, such as refilling the supply, can be taken before the supply reaches critically low levels, thereby maintaining uninterrupted service in healthcare settings.

In contrast, different alarms such as high pressure, low pressure, or warning light indicators pertain to specific parameters of the gas delivery system rather than overall supply levels, which is why the master alarm is the most appropriate answer in this context.