Can anyone tell me if a standard exists for the length per decade of
log-log graph paper used in time current curve (TCC) plots?
Since these were designed for tracing, the scales of every
manufacturers paper had to be the same. I've measured various
originals and copies, and the distance appears to be about 2.21 inches
per decade. However there is bit of variation between 2.20 to 2.23,
the distance for vertical decades of time in seconds also seem to be a
bit shorter than the horizontal distance for current in amperes.

It would be nice to know is there is some old ANSI standard or something that spells out how this paper is to be made.

It would be nice to know is there is some old ANSI standard or something that spells out how this paper is to be made.