ISO 20669:2017规定了脉冲涡流（PEC）测试技术，该技术用于在有涂层、绝缘和防风雨板存在或没有涂层、绝缘和防风雨板的情况下对铁磁性金属部件进行厚度测量。 ISO 20669:2017适用于由碳钢和低合金钢制成的在役部件在？100°C至500°C（在金属表面测量的温度）温度下的试验。组件的壁厚范围为3 mm至65 mm，涂层厚度范围为0 mm至200 mm。测试部件还包括直径不小于50 mm的管道。 本文件中描述的技术对部件的几何形状敏感，将该技术应用于其范围之外的部件将导致不可预测的不准确。本文件不适用于由点蚀引起的裂纹缺陷和局部金属损失的测试。 ISO 20669:2017未建立评估标准。评估标准应由双方之间的合同协议规定。

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.