Vacuum values
 

All,
I have what seems to me like a simple question. Is there a certain vacuum reading that I should see on my car, a 1990 190E? I am going to get a gauge to read it and see if it checks out. However when I did a search I couldn't find any values for what the vacuum should be, and under what conditions.

(I've replaced some intake pipes and they seal much better than the old ones, so I want to confirm that I've now got good vacuum).