Quote Originally Posted by irving2008 View Post
I was thinking on the lines of hacking apart a couple of cheap 200mm digital vernier units - that would give 0.01mm resolution (.0004thou)
The cheap chinese digital scale resolves 20480 lines per inch but it's hard to get the jitter down to less than 3 counts. I simply dump the bottom two bits and accept a stable 5120 counts per inch (approx .005mm res). Don't forget to clean the grit out if you buy one :D

It's 2x24 bit two's compliment, here's a link...

http://www.yadro.de/digital-scale/protocol.html