Cheng/Yang Correction - Micromeritics ASAP 2460 Operator's Manual

ASAP 2460 Operator's Manual
T =
1
T =
2
T =
3
T =
4
where

Cheng/Yang Correction

This factor corrects for the nonlinearity of the isotherm. It adds an additional term to the equations for
the different geometrics:
P
 
------ -
ln =
 
Po
where
G(L) =

=
246-42800-01 - Aug 2013
1 1
------------------ - ------------------ -
–
3 3
   
1 S – 1 + S
1 1
------------------ - ------------------ -
–
2 2
   
1 + S 1 S –
1 1
------------------ - ------------------ -
–
9 9
   
1 S – 1 + S
1 1
------------------ - ------------------ -
–
8 8
   
1 + S 1 S –
L d –
0
--------------
S =
L
1 1

G L  
-- - ----------- -
– 1 – ln

 1 
–
one of the Horvath-Kawazoe equations given above
degree of void filling;  is estimated by first computing the monolayer capac-
ity (Q ) with the Langmuir equation over the range of data points from
m
relative pressure 0.02 to 0.2 or the maximum relative pressure included in the
Horvath-Kawazoe analysis.  is computed as the quantity adsorbed over Q


Appendix C
.
m
C-29