Final line filters for instrument air shall be equipped with what kind of indicator?

Final line filters for instrument air are critical components in ensuring that the air supplied to instruments is clean and free of contaminants. Equipping these filters with a continuous visual indicator is essential because it provides immediate, ongoing feedback regarding the filter's condition. The visual indicator denotes the pressure drop across the filter, signaling to operators or technicians when the filter is becoming clogged or requires maintenance.

Having a continuous visual indicator allows personnel to quickly assess the operational status of the filter without needing to conduct detailed inspections or checks. This proactive approach helps in maintaining the quality of the instrument air and supporting the correct functioning of sensitive instrumentation, ultimately enhancing the safety and efficiency of medical gas systems.

In contrast, while a pressure gauge can provide useful information about system pressure, it does not indicate the filter’s specific condition over time. An audible alarm could alert personnel to an issue, but it may not provide the same level of constant monitoring. Similarly, a manual reset switch is not relevant in this context, as the aim is to continually monitor the filter's status rather than require an operator to manually intervene.