Micromeritics TriStar II 3020 - Calculations

TriStar II 3020 Appendix C
302-42828-01 - Dec 2012 C-11
c.) The walls of the cylindrical pore - the diameter of the empty pore is required to determine
the pore volume and pore area. End area is neglected.
Calculations
VI
I
Va
I
D=
Rc
I
A–
1 F+Pr
I
ln
-----------------------------------------
=
The volumes adsorbed (Va) are converted to the liquid equivalent volumes (V1, cm
3
/g):
where D is the Density Conversion Factor fro
m the Adsorptive Properties dialog.
The relative pressure (Pr
1
) is assumed to be close to unity so that substantially all the pores in the sam-
ple are filled.
The corresponding Kelvin core radius is calculated. Only pores smaller than this size will be included:
where
A = adsorbate property factor (the BJH Adsorptive Options dialog)
F = fraction of pores open at both ends (from the BJH Adsorption Report Options
dialog or the BJH Desorption Report Options dialog); assumed to be zero for
desorption
This radius will be adjusted for the thickness of the adsorbed layer during subsequent calculation steps.
Pore
Insignificant
compared to
core length
Wall