This test method describes a process for determining the uniformity and conformance to minimum/maximum specified thickness of coatings applied to newly manufactured steel pipe in a shop using noncontact electromagnetic gauges (NEMG) equipped with terahertz technology.

The procedures for in-line accuracy verification and adjustment of the NEMG are described herein.

This document contains the following appendices:
a) Appendix A (nonmandatory) – Theory of Coating Thickness Measurement Using NEMG Equipped with Terahertz Technology
b) Appendix B (nonmandatory) - Accuracy Verification using an In-line Internal Standard Sample