The DeFelsko STDS3 Certified Coated Metal Plates, Epoxy on Steel (Ferrous), for use with PosiTest G & GM and PosiPen A, B & C is ideal for verifying the accuracy and operation of coating thickness gages and are an important component in fulfilling both ISO and in-house quality control requirements. Many organizations require verification of gage accuracy at the test site each time a coating thickness gage is put into service and at frequent intervals during use. Ideal for this purpose, certified coating thickness standards have measured values traceable to a National Metrology Institution.