Hi,
I'm learning infusion and trying to get all the setup with minimal leaks. I'm using EC4 (i've fitted it with ball valve, vacuum gauge and air inlet valve), CP1 catch pot, Greisinger GDH 200-14 gauge at the very end. When pulling vacuum GDH 200-14 starts from 1012 mbar and drops to -2 mbar. Pump side gauge shows -1 bar, catch pot gauge shows -0.95 bar.
Questions.
1. I understand that gauges put closer/further from pump will show different values. Should I worry about GDH 200-14 showing -2 or it's just an measurement error I should ignore?
2. After pulling vacuum and clamping hose between pump and catch pot GDH 200-14 shows this:
@ 0 min -2 mbar
@ 5 min 34 mbar
@ 10 min 37 mbar
@ 15 min 38 mbar
@ 30 min 42 mbar
What is acceptable leak rate ?

It really depends on the part and the tooling - leaks are bad - but some are worse than others.  The thing that stands out to me is that the bag drops super fast initially and then the rate of "leak" goes way down after 5 minutes.  How big is the part and what quantity of fiber / core?  You may have a moisture / volatile problem especially if it is warm where you're working.  Usually a real leak will just keep leaking at a pretty steady rate.  You probably have a leak too - everybody has leaks - but not a huge one if you can get down to 0mbar (or -2).  Try leaving the part under the bag for an hour or two to boil off moisture - and then doing the drop test.  You may find it gets better.