Here's the situation...

Large plant with filtered breathing quality (D & E) air hard piped throughout the plant used for instrumentation and breathing air when airlines are used. Over 50 discharge points are available. This system is separate from the service air system (used for air tools and such).

This system is not used for airline rescue supply.

Question on testing for those with similar situation. At present, we test the air at the discharge point at the time we use it for breathing air. Does anyone test their system routinely in leiu of the time of use test we do and if so, from how many outlets?