Home / Service & Support / Product Knowledge / How to test Water Vapor Transmission & Water Vapor Permeance

How to test Water Vapor Transmission & Water Vapor Permeance

Jan 06, 2021

The three characteristics of material are very important in assessing the performance. The values are essential for industries of design, manufacture, and marketing.

Water Vapor Transmission, Water Vapor Permeance, Water Vapor Permeability

Water vapor transmission (WVT) is determined by dividing the rate of weight change by the area of the test specimen. Water vapor permeance is in general the degree to which a material admits water vapor. Water vapor permeability is related with the thickness of the material.

Calculation of Water Vapor Transmission, Water Vapor Permeance, Water Vapor Permeability

The permeance and permeability are calculated from the WVT. The permeance is calculated by dividing the WVT by the vapor pressure across the material under test. The permeability is calculated by multiplying the permeance by the thickness of the material.

The three characteristics of material are very important in assessing the performance. The values are essential for industries of design, manufacture, and marketing. Saicheng’ WPT-301B Water Vapor Permeability Tester is able to test the values of Water Vapor Transmission, Water Vapor Permeance, Water Vapor Permeability, which is a indispensable instrument for evaluating materials.

What is the difference between permeability and permeance?

Permeability measures how easily a fluid can flow through a material. Permeance, on the other hand, is a measure of the rate of fluid flow through a material per unit of fluid pressure differential. It is typically expressed in units of flow per unit area per unit of time.

We hope this helps and as always, we aim to ensure we can help and be proactive.

You can contact your Saicheng sales representative by email. Alternatively, complete the contact us form and we will get back to you as soon as possible.

Posted in Product Knowledge on Jan 06, 2021.

Jinan Saicheng Instrument, focusing on the R&D of packaging material testing instruments, provides you with cost-effective quality control solutions. We accept customization products for customer special need. We look forward to hearing from you!