I wouldn't waste much time getting an automated measurement system. It's so much quicker taking manual data. You could place all the meters together in one place and record with a movie camera. That method doesn't take up much of your precious time.
I've used a micro computer (from Freescale) that has 8 12-bit A/D's to automate this measurement. Did all the programming in C. But in reality, it's much easier to just read the meters.

Regarding Wayne's graph, I'm looking for 4-digit accuracy. If you're extremely lucky and spent a great deal of time, you *may* get 3-digit accuracy reading the graph. It's sooo much easier to just show raw data. Don't know why he's reluctant to do so.