mercalia wrote: you in the end filed down or some thing the teeth of the digital calipers didnt you to make sure your measurements were accurate and not measuring the wrong curvature?
er, no and no, not quite.
As I think I mentioned previously I eventually ground the 'internal' jaws of a caliper so they were slimmer, and I did this mainly to allow the caliper to be used more easily on 9/10/11s chain.
Calipers probably vary a fair bit, but the ones I used worked OK 'as is' on 1/8" and 3/32" chain. If you were clumsy I suppose the narrow part of the jaw could end up alongside a roller rather than on it; further grinding might yet be required to make the tool more idiot-proof in this respect.