belt tension?

i just changed the compressor/ power stearing belt on my GST and i was wondering how you guage the right amount of tension on the belt. It says 120 lbs but how do i know what is 120 lbs of tension. thnx in advance

Its a judgement call. Tight enough that it doesnt slip, but not so tight it puts excesive side loading on the bearing (good way to kill that accessory).

thanx kevin...you da bomb