I can't recommend this.... got one a few years ago, and it didn't work.  I explained to DigiSync guy what it was doing (not doing), to me it clearly was a defective unit...... he stopped communicating with me, never resolved it.  Still on the shelf, to me it's a brick.  I later picked up a Vacuumate, a very expensive tool that works perfectly.... it will bite your wallet hard.  You don't need anything that perfect......
I'd get either a Morgan Carbtune or set of vacuum gauges.  Be sure to calibrate (or at least know the deviation on each) the vacuum gauges.