ASTM E398: Testing the Water Vapor Permeability of Materials at Equilibrium Humidity

 

The ASTM E398 standard outlines the method for measuring the water vapor permeability of materials under specified relative humidity. This method is commonly used in the packaging and construction industries to ensure that materials serve as effective barriers against moisture. Compliance with the ASTM E398 standard indicates that the material meets the required levels of water vapor permeability, protecting products in various environments.

Key Testing Methods in ASTM E398

The ASTM E398 standard provides a method for accurately determining water vapor permeability:

Equilibrium Method

This method is conducted under controlled conditions, with the material tested at a constant relative humidity. It determines the permeability rate by measuring the weight of water that diffuses through the material over a defined period.

 

Application Areas of the ASTM E398 Standard

The ASTM E398 standard is particularly important in the following sectors:

ASTM E398-Certified Machines

Here are machines suitable for testing according to the ASTM E398 standard: