本文件规定了确定长期吸水率的设备和程序 通过扩散对试样进行检测。适用于隔热产品。它旨在模拟 产品在高相对湿度下的吸水率，约为100% 两侧和长时间承受水蒸气压力梯度，例如倒置的屋顶 或无保护的接地绝缘。 本试验不适用于所有类型的隔热产品。相关产品标准 应说明该测试适用于哪种产品（如有）。交叉引用:ISO 29768购买本文件时提供的所有当前修订版均包含在购买本文件中。

This document specifies the equipment and procedures for determining the long-term water absorption of test specimens by diffusion. It is applicable to thermal insulating products. It is intended to simulate the water absorption of products subjected to high relative humidities, approximating to 100 %, on both sides and subjected to a water vapour pressure gradient for a long period of time e.g. inverted roof or unprotected ground insulation. The test is not applicable for all types of thermal insulating products. The relevant product standard should state for which of its products, if any, this test is applicable.Cross References:ISO 29768All current amendments available at time of purchase are included with the purchase of this document.