Originally Posted by Yorkshiretea
I've got a question for you Derek, what that the possible increments between 50 and 55yds? I know John mentioned it possible to get two microns but that's pretty impossible with the human hand.
The 2um is the resolution of the read head and encoder strip, not just between 50-55.
This is not very relevant as what is important is the accuracy of the displayed range reading relating to the wheel position.
For example, a quartz watch oscillates at about 32Khz, but only has a second hand - it's the accuracy of time that is important.
So we have the display read in 0.1 yard increments (or meters) from min range 8 to 55+.
A 10um or 100um etc resolution read head would also be suitable if one was available at the right price and spec. The higer resolution sensor was actualy a lower cost at a better current / voltage spec