I'll second the KAB Speed Strobe. I use on on my Galibier and really like it. Remember, anytime you check the speed be sure to have the stylus tracking in as dynamic a passage of music you have.
As far as what you may be able to do if your table is a bit off, that's a bit tougher. You may be able to play with the belt tension, and maybe even material, to improve things if the speed is not off too much.
As far as what you may be able to do if your table is a bit off, that's a bit tougher. You may be able to play with the belt tension, and maybe even material, to improve things if the speed is not off too much.