That's a very good question, Dusty. Aside from very expensive rulers, I haven't found any with published accuracy specs. So you get what you get, and then you have to calibrate it yourself.dusty wrote:What level of accuracy is reasonable to expect of a ruler or tape measure that is marked in increments of 1/16" or even 1/32".
1/16" = .0625"
1/32" = .03125"
If expecting measurement accuracy at the .005" level I hope you are not marking the cut point with a lead pencil.
As for accuracy vs. resolution, it's real easy (assuming good near-field vision) to interpolate a measurement halfway between graduation marks. That would be the minimum acceptable accuracy to me. Interpolating to 1/4 of the smallest graduation isn't difficult either.
That said, I'm not a typical user. I have one eye that is very nearsighted, so without glasses it acts like a magnifying glass up close. I can easily see individual pixels on a 300 DPI printout -- those would be about 0.003" wide.