I work for a steel service center and we are currently going through ISO certification. At present, we check tape measures on a weekly basis with a 6" steel rule. I am hearing that this is not acceptable in that the "run out" on a tape measure is greater the further out you go. My question is this... Is there a standard length to check them at? I am being asked to supply a "certified" steel rule at lengths of 60" and 120". I can find the 60" but not a 120". As an after thought, the minimum tolerance that we work with is +0/-1/32. Any help would be greatly appreciated.