Calibration of a novel instrument for the investigation of small permeation fluxes of gases through membranes

• The calibration of a permeation measurement equipment introduced earlier is showed.
• The calibration is shown to be membrane temperature independent.
• The sensitivity and the reproducibility of the equipment are determined.

In this study the calibration and the determination of the sensitivity and reproducibility of a permeation measurement equipment are presented. It is showed that the calibration constant describing the relationship between the material current entering a vacuum chamber through a membrane and the pressure increase over the base pressure in this chamber is dependent on the type of gas used but independent of the membrane temperature. The reproducibility of the calibration constant is approx. ±13%, which can be accepted as the reproducibility of the equipment. The results indicate that the minimum material current required for the determination of the transport parameters in a mounted membrane is in the range of 10-11⌊mols-1⌋ and the maximum measurable permeating current is 5 orders of magnitude higher than this. Using various mountable membrane thicknesses this means that the transport properties of a wide range of materials can be investigated with the equipment.