I bought a Drumdial tuner and it works very well. It measures the tension at each lug. You need to experiment with it on your drums. The Drumdial comes with a "suggested" guide giving you approximate numbers for tensioning individual drums. For example, I tune my 12 inch tom to 77 on both the top and bottom heads and it sounds great...
The tension "number" will also change depending on what type of heads you put on your kit ie. clear or coated...
Hope this helps,
JEFF