I guess it depends on how much clout the auditor has. At the least I would give a listen along with some polite head nodding, and ask where in the specs it says that. You know....those code books "all blend together after a while and we always appreciate the help in keeping everything straight".
I would avoid promising to fix the problem until I had a chance to verify there really is a problem. If it is, I address it immediately; if not, I keep the "suggestion" in mind.
Calibrating welding machines has been a pet peeve of mine as well. Our shop is certified for bridges so we have to comply with AWS D1.5 and do our checks every 3 months. But no one seems to agree on the best way to do that. What I can't justify is putting a load cell on our power supplies, measuring varied outputs, and plotting a graph to correlate machine readouts to the measured output. It takes a lot of time, the results go out the window when welding conditions change, and our people like to play "musical machines". I try to keep my calibrations as simple as possible and so far, auditors have not taken exception to my methods. But if someone has a good way to do this, I'm all ears!
Chet Guilford