One detail that attracted my interest so to explore too, are those single ball rota-meter ( rotameter / flowmeter ) for measuring air flow.
And so I just purchased one of those 5-25 L/minute ( flow meter ) so to use it as one comparison point in one review that I am planing to do.
Most manufacturers describe as Max specification for those pumps from 20L to 24L.
But most of the on-board flow meters in the rework stations comes with a very different scale from 1 to 6 but definably this measurement is not Air L/Min.
I did a small discovery that HAKKO did use a flow meter of a L/Min scale in their FR-802, and I am posting a picture of it.
One nice tip in the HAKKO FR-802 users manual is : To never use lower air flow than 5 L/Min.
My current answered question is what represents this scale of 1-6 at those air-work stations?
While I am still looking for answers I will post some pictures so to trigger your interest too.