Micromeritics ASAP 2460, Operator'S Manual

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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 )
Q
0 err

Q
0
10
YI err

1.0 –
 
=
SDP

Q
0
6.023 10
23
  
22414 cm
3
10
18
nm
2
m
2
-----------------------
 
 
 
--------------------------------------------------------
=
Q
 
log Q
0
 
RT

E
0
---------
N
Po
P
------- log

N
– log =