I am in charge of Gauge Control at an automotive assembly plant (Supplier to bigger companies) & my company has recently started using Ultrasonic Inspection of Resistance Spot Welds (NDT). I have all of the proper information entered into my database, but the calibration certificates that came with the equipment state to refer to Calibration Standard N24: PFM. -NO 1841, which I am not familiar with. Can anyone give me some info on what this is and where I can locate it?
Thanks

I'm not familiar with the standard in question, but I'll bet that the people who gave you the certificate are. Why not ask the manufacturer? You should also be sure that the calibration certificates indicate traceability to national standards (NIST in the US) and include uncertainty results. Note that sometimes the calibration certificates that come with new equipment won't satisfy ISO (or other) requirements, and it's best to have the device(s) calibrated by an independent source prior to use. Another good reason to do this is that even if the calibration documentation is in order, it represents the state of the device before it was shipped, and all of the banging around of shipment can throw things off.