What is the primary function of a local alarm system in medical gas setups?

The primary function of a local alarm system in medical gas setups is to ensure visible and audible surveillance of medical gas source equipment. This is crucial in a healthcare setting where the proper function of medical gas delivery systems is vital to patient safety and care. The local alarm system provides immediate alerts in the event of equipment malfunction, pressure drops, or other issues that could compromise the availability or safety of medical gases. By being both visible and audible, the alarm ensures that medical staff can respond quickly to any potential problems, thereby preventing interruptions in medical gas supply that could adversely affect patient treatment.

Monitoring patient health continuously and providing remote alerts to staff fall outside the primary scope of local alarm systems, which are more focused on the gas equipment itself rather than direct patient monitoring or communication over long distances. Additionally, controlling the flow of gas to patients is not an alarm system's function; rather, it's the role of other equipment in the medical gas delivery system. Thus, option C stands out as the correct answer, as it aligns directly with the core purpose of local alarm systems in medical gas setups.