"GB/T 34430.4-2024 Ships and Offshore Technology, Protective coatings and inspection methods, Part 4: Automated Measuring method for total water-soluble salt content" stipulates the automatic Measuring method for the total water-soluble salt content on the surface of steel before painting of ships and marine engineering structures. The standard is applicable to special seawater ballast tanks, empty tanks of bulk carriers and oil tankers, and cargo tanks of crude oil ships. The concentration of ion pollutants on the surface of steel is rapidly assessed by Conductivity Meter. This method can be equivalent to GB/T 18570.9-2005 and provides an important basis for ship coating mass control. It will be officially implemented on June 1, 2025.