This European Standard specifies the equipment and procedures for determining the long-term water absorption of test specimens. It is applicable to thermal insulating products. This European Standard specifies two options: 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.