That moment at the supply house that finally made me check my meter's accuracy

Last Tuesday I was waiting at the counter at Platt in St. Louis and the guy next to me was complaining about a Fluke meter that was off by 4 volts on a 277 circuit. I laughed it off until he showed me his calibration sticker was expired by two years. I got home and checked my own Klein meter against a new one my buddy brought over and mine was reading 1.2 volts low on a standard 120 outlet. That little difference could have been the reason I chased a ghost issue on a lighting circuit a month ago where everything tested fine but lights flickered randomly. Now I'm gonna send mine in for calibration every year no matter what. Has anyone else had a meter drift on them without noticing?

2 comments

2 Comments

schmidt.grace3d ago

Wait, so you're telling me my meter could be gaslighting me this whole time and I wouldn't even know it? That's like finding out your tape measure has been lying about your height for years (which, trust me, would be a real bummer at 5'8"). I checked my old Fluke last night against my neighbor's brand new one and mine was off by almost a whole volt on a 208 circuit, so now I'm wondering how many "mystery problems" I've solved with a bucket of luck and a prayer.

gonzalez.grant3d ago

Calibration drift hits harder than most people realize because it's not just about accuracy, it's about how your brain builds habits around wrong readings. If your meter's been reading 209 when it's actually 208 for years, you've basically trained yourself to expect +1V on every 208V circuit you touch. Might explain why some guys swear they can "feel" when a circuit is hot, when really their equipment is just consistently lying to them.