本文件规定了一种试验方法，用于在环境温度下测定与氮气混合的氧气的最小体积分数，该方法支持在高于ISO？4589-2规定的规定气体速度下燃烧小型垂直板试样。 注？结果用高气速氧指数（HOI）表示。 此外，本文件规定了用于测定HOI的试验装置。 本试验方法适用于厚度不超过2mm的板材。它也适用于由指定试样夹垂直支撑的柔性板材。

This document specifies a test method for determining the minimum volume fraction of oxygen, in admixture with nitrogen, at ambient temperature, that supports combustion of small vertical sheet test specimen under a specified gas velocity that is higher than that specified in ISO 4589-2. NOTE            The result is expressed as a high gas velocity oxygen index (HOI). In addition, this document specifies the testing apparatus for determining the HOI. The test method is applicable to materials in the form of sheets up to 2 mm thick. It is also applicable to flexible sheet materials that are supported vertically by a specified specimen holder.