The traceability chain for a consumable has six links, and most labs only
The auditor picked lot PT-2409-117, a 47 mm, 0.45 µm PTFE membrane, and asked for the calibration certificate of the balance that weighed the 240 g of polymer going into that batch. The lab produced a certificate. It was for a different balance, in a different building, and the calibration had expired 11 days before the extrusion run. That single broken link turned an otherwise clean ISO 17025 assessment into a finding, and the finding was not about the membrane’s performance. The mem...
