Should You Call With the Nut Low Draw On the Turn???

[PokerProdigy]

Many times when the turn arrives I am unsure whether or not I should call a bet to try and hit the nut low, usually I just make the call because the pot is (usually) fairly large. But lately, I have been playing the 6 max tables, so the pot is usually not as large, and I am wondering when I should call with my nut low draw and when I should fold it? In other words, if I only have the nut low draw (with no hopes at winning the high side of the pot) then how many bets/how much money should be in the pot in order for me to (correctly) call one bet? Another way of putting this is, what do the pot odds need to lay me on the turn in order for me correctly call one bet in hopes of hitting the nut low?

P.S. For the sake of argument, lets also assume that I don't have any counterfiet protection. However, it'd be nice to know what the pot odds need to be in both situations if you know them off hand.