A theoretical analysis of the diffusion porometer: Steady diffusion through two finite cylinders of different radii

✍ Scribed by David C. Chapman; Robert L. Parker

• Publisher: Elsevier Science
• Year: 1981
• Weight: 555 KB
• Volume: 23
• Category: Article
• ISSN: 0002-1571
• DOI: 10.1016/0002-1571(81)90088-1

✦ Synopsis

Calibration and use of the diffusion porometer are imprecise because of imperfect understanding of steady diffusion through a porous material. The case of a fiat plate with uniformly distributed right circular cylindrical holes is approximated by diffusion through two finite right circular cylinders: one representing the pore, and one representing the area into which vapor diffuses --its size determined by the mutual interference with neighboring pores. An exact three-dimensional solution is presented. It is found that for large pore spacing the empirical result of Holcomb and Cooke is excellent, but for close pore spacing some error occurs. A method for calculation of true calibration plate resistance is described as well as a method for estimating pore size for an unknown plate or membrane.