ISO 20669:2017 specifies the pulsed eddy current (PEC) testing technique used to perform thickness measurement on ferromagnetic metallic components with or without the presence of coating, insulation and weather sheeting.
ISO 20669:2017 applies to the testing of in-service components made of carbon steel and low-alloy steel in the temperature of 100 C to 500 C (temperature measured at metal surface). The range of wall thickness of components is from 3 mm to 65 mm and the range of thickness of coatings is from 0 mm to 200 mm. The tested components also include piping of diameter not less than 50 mm.
The technique described in this document is sensitive to the geometry of the component and applying the technique to components outside of its scope will result in unpredictable inaccuracy. This document does not apply to the testing of crack defects and local metal loss caused by pitting.
ISO 20669:2017 does not establish evaluation criteria. The evaluation criteria shall be specified by the contractual agreement between parties.