Turn the crank 90 degrees and read the indicator.
Here, we are only 0.001 out. That is REALLY good. That NEVER happens. Oh well, must be our lucky day. Write 0 on the top of the bell housing (because we forgot to in the previous photo) and write 1 (or one thousandth of an inch) at the 90 degree mark. You better write it down or you will end up chasing your tail.