ASTM D1653 is a critical standard developed by ASTM International that outlines test methods for measuring the water 

vapor transmission rate (WVTR) of organic coating films. This standard is essential for industries relying on protective 

coatings, including automotive, aerospace, construction, and packaging, where moisture resistance directly impacts 

product performance and longevity.

Importance of Water Vapor Transmission Testing

Water vapor transmission through coatings can lead to corrosion, delamination, and reduced durability. ASTM D1653

 provides reliable methods to assess a coating's ability to resist moisture permeation, helping manufacturers:

Ensure coating effectiveness in humid or wet environments

Compare different formulations for optimal barrier properties

Meet regulatory and industry requirements for moisture resistance

Testing instrument：WVTR-C6 Water Vapor Permeability Tester

Key Test Methods in ASTM D1653

The standard describes two primary methods:

1. Desiccant Method (Dry Cup)

Measures water vapor transmission from a humid environment into a desiccant-filled chamber

Coated specimens are sealed over a dish containing a desiccant (e.g., anhydrous calcium chloride)

Weight gain over time determines WVTR

2. Water Method (Wet Cup)

Evaluates transmission from liquid water through the coating into a controlled atmosphere

The specimen is sealed over a water-filled dish, and weight loss is monitored

Both methods require controlled temperature and humidity conditions (typically 37.8°C ±1°C and 90% ±2% RH) for 

accurate results.

Applications in Industry

ASTM D1653 is widely used for:

Protective coatings (anticorrosive paints, sealants)

Packaging materials (food, pharmaceutical barriers)

Architectural coatings (exterior paints, waterproofing membranes)

Conclusion

By adhering to ASTM D1653, manufacturers can ensure their coatings meet stringent moisture resistance standards, 

enhancing product reliability. Implementing this test method supports quality control, R&D improvements, and 

compliance with industry specifications.