Dollimore-Heal Adsorption; Pore Diameter; Pore Length - Micromeritics ASAP 2460 Operator's Manual

ASAP 2460 Operator's Manual

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:
 
D = 2r
i k
The average pore diameter is the arithmetic mean of the diameters that bound the interval.
D +

i
------------------------ -
D =

i

Pore Length

A +
p i 
--------------------- -
l =
i
D

4
--------------------------------
A =
p i 

V = C

p

------------------------------------------------------------ -
C =



2 r
D
i
-------------
t =
2 r –
k

r
k i 
----------------------------------
r =
k
246-42800-01 - Aug 2013
 
P + t P
i i
D

i + 1

2
10 8
i
8
  
10 V
p
D
i
    
D Q – Q – t 10
i 1 – i
D
i
    
+ t P – t P
k i i + 1

+ r

k i + 1
2
8

A – 2 t l
 
p cum i cum
2


Appendix C

C-25