'95 Sentra, how do I know when the Power steering belt is tight enough

[ReaperBJJ]

So I posted a while back that my idler pulley in my ga16 sheared off while driving on the highway one day, shreading my alternator belt. I got a new belt and pulley and put it in but you have to take the power steering belt off to get the alternator belt on. Once I put everything back together I tightened the tensioner on the PS belt to where the belt seemed taught, but the next day when a cold front hit, I had no power steering and the belt squeaked all the time. So I tightened it a lot more and that seemed to fix it, cept for a brief squeak on start-up and an occasional weird sound the from the PS pump(sounded like an air bubble or something ), but everything worked just fine. Now living in the grand state of Minnesota, we got another cold front and I've been facing temperatures between -45 and and -30 after windchill. The car does the same thing for a little bit, squeaks at start up, and the occasion odd sound I explained, but now, it's so cold again that for about the 1st minute or so it's running I don't have PS again.

Anyway, can someone tell me is there any way to tell that I have the belt the right tension? I don't want to over tighten it, and the owners manual says nothing just to "take it to a qualified Nissan mechanic"