Micromeritics ASAP 2460 - Dollimore-Heal Adsorption; Pore Diameter; Pore Length

ASAP 2460 Operator’s Manual Appendix C
246-42800-01 - Aug 2013 C-25
Dollimore-Heal Adsorption
The calculations for the Dollimore-Heal reports are the same as those for BJH, except for the calcula-
tion of average pore diameter and pore length.
Pore Diameter
Pore diameter is determined from the Kelvin radius and thickness equation:
The average pore diameter is the arithmetic mean of the diameters that bound the interval.
Pore Length
D
i
2r
k
P
i
tP
i
+=
D
i
D
i
D
i1+
+
2
-------------------------


=
l
i
A
pi
10+
D
i
----------------------
8
=
A
pi
410
8
V
p

D
i
--------------------------------
=
V
p
 C

D Q
i1–
 Q
i
– t 10
8
 A
pcum
 2 tl
icum
––=
C

D
i
2 r
k
tP
i
+ tP
i1+
–
-------------------------------------------------------------


2
=
t
D
i
2 r
k
–
-------------
=
r
k
r
ki
r
ki 1+
+
2
----------------------------------
=