TABLE OF CONTENTS The units of permeability may appear in several forms, as spelled out in Chapters 1 and 2, albeit the same symbol P i is used for each set of units. For convenience, the transformation or conversion between the several forms are furnished in spreadsheet notation as follows, with corresponding spreadsheet examples appended for each calculation.
| Column | Equation or Designator | Spreadsheet Formula |
|---|---|---|
| A | Basic P i (units of 10 ?9 cm 3 per cm 2-sec-cm Hg/cm) | (given) |
| B | Basic P i* (10 ?3)(76), 10 ?6 cm 3 per cm 2-atm/cm or 10 ?6 cm 2 per sec-atm | A10*POWER(10, 3)*76 |
| C | Thickness = ? m (microns or 10 ?4 cm) | (fixed) |
| D | Overall P i = Basic P i* (10 ?9)* (76/22,414)* [1/ ? m(10 ?4)]*10 1 (units of g-moles per cm 2-sec-atm | A10*POWER(10, ?9)*(76/22,414)*(1/C10*POWER(10, 4))*10 |
| E | Overall P i = D*(30.48) 2* (3600/453.9)*(1/14.696), lb-moles per ft 2-hr-psi | D10*POWER(30.48,2)*(3600)/453.9*14.696 |
| F | Area, cm 2 | (set at 1000 cm 2) |
| G | P L P V | (set at 1 atm) |
| H | Permeation Flux (g-moles/1000 cm 2-sec-1 atm difference, where 929 cm 2 = 1 ft 2) | D10*F10*G10 |
| I | Permeation Flux (lb-moles/ft 2-hr-atm difference) | H10*3600/453.6*(929/1000) |
| J | Diffusivity, cm 2/sec at 1 atm | B10*G10 |
