Cheers mate, that means the 18.99 Amazon specials all the other guys use that have never seen a calibration sticker probably shouldn’t be getting used to record current draw during maintenance.@Boing89 Hey! Ex RAF here too! If the values of the measurements are being recorded for certification the meter should be in calibration - the values are not valid without it - it's a requirement. I also use a Calibration Card before testing, takes 2 mins and confirms nothing amiss since calibration was carried out.