Micromeritics ASAP 2020 Confirm Operator's Manual page 370

ASAP 2020 Confirm
c. Pore diameters and radii are adjusted for the change in thickness of the adsorbed wall
layer during this interval. If new pores were opened during this interval, the average
diameter is adjusted by the change in layer thickness during the second portion of the
desorption interval as follows:
D
avg
The layer thickness change during the whole interval is added to diameters of previ-
ously opened pores as follows:
D
avg
(not including D
The layer thickness change desorbed during this interval also is added to the radii
corresponding to the ends of the pressure intervals as follows:
Rc
for all except Rc
Steps a to c are repeated for each pressure interval.
After the above calculations have been performed, the diameters corresponding to the
ends of the intervals are calculated as follows:
Dp
for all Rc
The remaining calculations are based on DP
are only done for values that fall between the Minimum BJH diameter and the Max-
imum BJH diameter specified by the operator on the BJH Adsorption Report Options
dialog box or the BJH Desorption Report Options dialog box.
1) Incremental Pore Volume (Vp
2) Cumulative Pore Volume (Vp
C-18
2 Td 
= D +
avg
Knew Kold
2   Tw 
= D +
avg
Jnew Jold
)
avgK
Tw
= Rc +
Jnew Jold
.
K+1
 
= 2 rc
J J
including Rc
J K+1
D 2
avg
 Lp  
---------- -
Vp = 10
I
I I
2

VP = Vp for J 1
CUM J
1  

.
, D
(I) avg(I)
, cm 3 /g):
I
16 2 2
cm /A
, cm 3 /g):
CUM(1)
  
Appendix C
, and LP . These calculations
(I)
202-42811-01 - Mar 2011