ISO 16535:2019

This document specifies the equipment and procedures for determining the long-term water absorption of test specimens. It is applicable to thermal insulating products.
This document specifies two methods:
— Method 1: Partial immersion;
— Method 2: Total immersion.
The long-term water absorption by partial immersion is intended to simulate the water absorption caused by long-term water exposure.
The long-term water absorption by total immersion is not directly related to the conditions on site, but has been recognized as a relevant condition of test for some products in some applications.