How do you test old style pcv ?

Thanks Guys! But your kinda missing my issue in a round about way.

if the ball is not seating properly because the thing is garbage from bad production it could be sealing one moment and not sealing as the ball inside turns. Kinda like a bad valve job. If that makes sense. Typically that valve is closed and not sucking at idle or up to a certain amount of pull like say 5”hg after 5”hg it pulls off the seat creating the suction into the crankcase. But if the ball does not always seat it leaks. As for a spring- the spring can or cannot be there to control the ball especially when it’s a plastic ball because plastic is a lot lighter than metal.
I understand how it works but just could not find a spec to test when it “pulls open.” After all the dialogue- I now assume there is no spring or spec.

thank you!