Al,
I have been working with the endoscopy processing equipment manufacturers for a few years, and the quality of air that they need is “instrument grade air”, not to be confused with instrument air as described in NFPA 99.
I am not near my office this week, where I have the exact description of instrument grade air.
To summarize, less than 1 mg particulate, and less then 3 deg. C dew point.
I will provide additional documentation when I have time.