SepraTek has developed permeation membrane analyzers which are able to precisely, rapidly and directly characterize the permeation behaviors of gas, liquid, and vapor molecules through membrane, respectively, by continuous-flow technique. They are also very effective to investigate interactive properties of a polymeric material with its exposure to a specific circumstance, like a liquid, vapor or gas, which makes them more than permeation membrane analyzers.

Permeation Membrane Analyzer is to generate the permeation transient curve of permeate through a membrane and to determine permeability, diffusivity and solubility coefficients from the transient curve. The analyzer is composed mainly of three constituents; feeding system, membrane cell, and measuring and data acquisition.

Measuring and data acquisition system generates two permeation transient curves in real time and display them on computer monitor. These two transient curves are created by voltage signals emitted from the pressure transducer (PT) and mass flow meter (MFM) produce voltages, respectively, corresponding to the permeation magnitude when permeation happens through the membrane.

The transient determined by the MFM has a slight retarded response to the permeation because of occurrence of some friction in flowing permeate through the MFM, resulting in giving somewhat larger response time and smaller diffusion coefficient than their real values, but permeability at steady state can be measured accurately from a level-off value in the transient curve.

The permeation transient measured by the PT has a real response to the permeation, which can give a correct diffusion coefficient, but the absolute value of permeability is not possible to obtain from the transient curve.

Therefore these two permeation transients are employed complementarily to determine permeability coefficient and diffusion coefficient which are automatically calculated by a computer program after the data acquisition. The dual detection system has an enough resolution to detect a very small instantaneous flux.