Ball flowmeters

Does anyone work with ball flowmeters to check the vacuum ? Does anybody know where to find cheap ones in the EU or China ? The ones I find are very expensive (+ €150) and I’m looking for a cheaper solution.

Thanx

I bought one way back from I think Airtech, or Composites one, however I didnt like it. I know theyre used often in RTM as a fast indication of leak, but I think the sensitivity isnt high enough for infusion process. Personally, I think sticking with a digital absolute pressure gauge at the resin inlet is the best method. But then again, maybe I used the product incorrectly. Would be interested to hear yours, or others feedback on this.

We don’t use it for vacuum infusion, but I’ve found some cheap ones on aliexpress.