本文件规定了一种软钎焊剂有效性的评估方法，称为润湿平衡法。根据两种助焊剂（例如，标准助焊剂和测试助焊剂）促进液态焊料润湿金属表面的能力，对它们的比较功效进行了定性评估。该方法适用于ISO 9454-1中分类的所有液态助焊剂类型。注:希望未来使用改进技术获得试验表面可重复范围的发展将使评估通量效率的方法能够定量化。因此，本方法中包含了几种制备试样表面的替代程序。

This document specifies a method for the assessment of the efficacy of a soft soldering flux, known as the wetting balance method. It gives a qualitative assessment of the comparative efficacy of two fluxes (for example, a standard and a test flux), based on their capacity to promote wetting of a metal surface by liquid solder. The method is applicable to all flux types in liquid form classified in ISO 9454‑1. NOTE It is hoped that future developments using improved techniques for obtaining a reproducible range of test surfaces will enable this method for assessing flux efficacy to be quantitative. For this reason, several alternative procedures for preparing the surface of the test piece are included in the present method.