Horvath-Kawazoe; Slit Pore Geometry (Original Hk - Micromeritics ASAP 2020 Confirm Operator's Manual

ASAP 2020 Confirm

Horvath-Kawazoe

A relative pressure lower limit is determined such that L-d
points less than this limit are discarded. For each collected relative pressure point, values of L
are chosen in an iterative manner, and the relative pressure (P/Po) determined by solving one
of the following equations:
• Slit Pore Geometry (original Horvath-Kawazoe)
• Cylinder Pore Geometry (Saito/Foley)
• Sphere Pore Geometry (Cheng/Yang)

Slit Pore Geometry (original HK)

When you use the original Horvath-Kawazoe
each value of P. The value of L is determined when the solved-for relative pressure is within
0.1% of the collected absolute pressure.
P
ln ------ - =
Po
where
K
R
T

1. Horvath, G. and Kawazoe, K., J. Chem. Eng. Japan 16(6), 470 (1983).
C-22
32 4

K IP 10 JA /J cm

------ - ------------------------------------------------- -
RT
4
   
L 2 d –
0
= Avogadro's number (6.023 x 10
= gas constant (8.31441 x 10
= analysis bath temperature (K), from an entered or calculated
value on the Po and Temperature Options dialog
= gas solid nuclear separation at zero interaction energy (Å),
where:
Z = sample equilibrium diameter at zero interaction energy (Å) from the
S
Horvath-Kawazoe Physical Properties dialog
Z = zero interaction energy diameter from the Horvath-Kawazoe Physical
A
Properties dialog
0
1
method, the following equation is solved for
4 4


----------------------------- - ----------------------------- -
–
3
   
3 L d – 9
0
23
)
7 ergs/mole K)
Appendix C
never equals zero. All pressure
10 4
 
-------------- - -------------- -
– +
9 3
   
L d – 3 d 9
0 0
Z
---------------- -
202-42811-01 - Mar 2011
10

9

d
0
+ Z
S A
2