What feature should final line filters for instrument air have?

Final line filters for instrument air should have a continuous visual indicator showing the status of the filter life. This feature is essential for ensuring that operators can easily monitor the condition of the filter without needing to perform manual checks. A visual indicator allows for proactive maintenance, which can prevent potential issues related to filter clogging or degradation that could affect instrument air quality.

Having a clear and continuous way to assess filter life enhances operational efficiency and safety within medical gas systems. It provides immediate feedback to technicians, allowing them to take necessary actions, such as cleaning or replacing the filter when it reaches the end of its effective life.

Other options, while they may have their benefits in specific situations, do not provide the same level of immediate, ongoing visibility regarding filter performance as a continuous visual indicator. An automatic flushing mechanism may not be necessary for all systems and could introduce complexity; a built-in pressure gauge is useful for monitoring pressure but doesn't directly inform filter condition; and a filter replacement alarm may not provide the real-time feedback that a continuous visual indicator does.