Previous Engineered Products by S.E.A. Engineering

Model S684-3 Three-Cell Automated Water Vapor Diffusion Apparatus Combination Cell

This system uses a unique combination cell design. The cell sets up a moisture gradient across a test specimen by maintaining a moisture source on one side of it and a moisture sink on the other side. The source is water held behind a membrane, and the sink is dry air behind another membrane. The cell may be used to do moisture diffusion tests for:

The Canadian Government Standards Board Standard

Cell Features

• Specimen Position (Air Gap) on the Wet Side Can Be Adjusted Anywhere in the Test Gap from Right Against the Wet Membrane to Against the Specimen from Outside the Cell Without Opening It
• The Air Gap on the Dry Side of the Specimen Can Be Adjusted with the Use of Spacers Provided from Zero to 10 Millimeters in Increments of 1 Millimeter
• The Cell Can Be Used for Making Absolute Measurements of the Water Vapor Diffusion of a Wide Range of Textile Materials, Including Those That Have Microporous or Hydrophilic Laminations or Coatings
• The Moisture Mass Flow Measurement Can Be Made Using a Weight Measurement Method (by a Computer) or a Volume Measurement Method (by Hand)
• Measurements Are Made Without Opening the Cell Meaning No Disturbance of the Atmosphere in the Cell During a Test Leading to More Reliable Results
• Dry Air Flow Is Horizontal Across the Dry Side Cavity
• The Model 643 Cell Has a Radial Air Flow & Can Be Readily Substituted for Use in the Automated Systems

Model S684-3 Three-Cell Automated Water Vapor Diffusion Apparatus

A Water Vapor Diffusion Apparatus (WVDA) is an instrument that is used to measure the rate at which water Vapor diffuses through fabrics. The Model S684-3 Automated Water Vapor Diffusion Apparatus (AWVDA) is a multi-cell system that enables an operator to run three separate tests simultaneously under computer control. This model consists of a workstation supporting the test hardware, a data acquisition module, and interface boards that mount in a PC.

The workstation provides space for three Water Vapor Diffusion (WVDC) Cells on laboratory retort stands and three associated auxiliary water reservoirs mounted on top-loading balances. The workstation also provides mounting for the cell water fill reservoirs and the drying columns, flow meters, regulators, and tubing for the dry air supply system.

The system uses a unique combination cell design which may be used to do moisture diffusion tests to the Canadian Government Standards Board (CGSB) Standard or the Van Beest and Wittgen (VBW) method. This cell is similar to the combination cell used in the model 643 manual WVDA, except that the dry air flow through the air-side half-cell is from side to side as opposed to radial.

The cell creates a moisture gradient across the specimen by providing a means for mounting the specimen between a water source and a water sink. The source is water held behind a "wet" membrane, and the sink is dry air flowing behind a "dry" membrane. Moisture diffusion is measured by the computer as a mass loss from the water cavity behind the wet membrane. Moisture diffusion can also be measured manually as a volume loss.

Cell Set Up Positions

When setting up in the CGSB mode, the wet membrane, typically made from Teflon, is above the test specimen and the dry membrane, also made from Teflon, is below. In VBW mode, the dry membrane, typically made from Teflon, is above the test specimen and the wet membrane, made from filter paper, is located below.