Appendix C ASAP 2460 Operator’s Manual
C-38 246-42800-01 - Aug 2013
Error of Monolayer Capacity (cm
3
/g STP):
Micropore surface area (m
2
/g):
where
= molecular cross sectional area of gas (nm
2
) from the Adsorptive Properties
window
Dubinin-Astakhov
The Dubinin-Astakhov equation is:
where
= the affinity coefficient of the analysis gas relative to the Po gas, from the
Dubinin Adsorptive Options window
E
0
= characteristic energy (kj/mol)
N = Astakhov exponent, may be optimized or user entered from the Dubinin
Report Options window
P = equilibrium pressure
Po = saturation vapor pressure of gas at temperature T
Q = quantity adsorbed at equilibrium pressure (cm
3
/g STP)
Q
0
= the micropore capacity (cm
3
/g STP)
R = the gas constant (0.0083144 kj/mol)
T = analysis bath temperature (K)
SDP
Q
0
6.023 10
23
22414 cm
3
10
18
nm
2
m
2
-----------------------
--------------------------------------------------------
=
Qlog Q
0
RT
E
0
---------
N
Po
P
-------log
N
–log=