Gemini VII
Appendix C
239-42828-01 - Dec 2012
C-21
Sphere Pore Geometry (Cheng/Yang)
P
Po
-------
ln
6
N
1
*
12
N
2
*
22
+
L
3
10
32
J
A
4
/
J
cm
4
RT L
d
0
–
3
----------------------------------------------------------------------------------------------------------
=
d
0
L
-----
6
1
12
------
T
1
1
8
---
T
2
+
–
d
0
L
-----
12
1
90
------
T
3
1
80
------
+
T
4
+
When you use the Cheng/Yang
11
method, the following equation is solved for 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.
where
R
=
gas constant (8.31441 x 10
7
ergs/mole K)
T
=
analysis bath temperature (K), from an entered or calculated value on the Po
and Temperature Options dialog
d
0
=
where:
D
A
= molecular diameter (Å) from the Horvath-Kawazoe Physical Properties
dialog
D
S
= diameter of sample atom (Å) from the Horvath-Kawazoe Physical dialog
L
=
pore width (nucleus to nucleus) (Å)
P
=
equilibrium pressure (mmHg)
Po
=
saturation pressure (mmHg)
N
1
=
4
L
2
N
S
, where N
S
= number of sample atoms/cm
2
at monolayer
N
2
=
4
(L - d
0
)
2
N
A
, where N
s
= number of gas molecules/cm
2
e*
12
=
, where
*
22
=
, where
T
1
=
T
2
=
D
A
D
S
A
+
2
-----------------------------
A
S
4
d
S
6
-------------
A
S
6
MC
2
S
A
S
S
------
A
A
------
+
-----------------------------------------------
=
A
A
4
D
A
6
---------------
A
A
3
MC
2
A
A
2
-----------------------------------------------
=
1
1
S
–
3
-------------------
1
1
S
+
3
-------------------
–
1
1
S
+
2
-------------------
1
1
S
–
2
-------------------
–
Summary of Contents for Gemini VII 2390a
Page 1: ...Gemini VII Operator s Manual V3 02 239 42828 01 Jan 2014...
Page 4: ......
Page 12: ...Table of Contents Gemini VII viii 239 42828 01 Nov 2013...
Page 36: ...Menu Structure Gemini VII 2 14 239 42828 01 Dec 2012...
Page 192: ...Service Test Gemini VII 6 24 239 42828 01 Dec 2012...
Page 217: ...Gemini VII Report Examples 239 42828 01 Dec 2012 7 25 Isotherm Linear Plot...
Page 218: ...Report Examples Gemini VII 7 26 239 42828 01 Dec 2012 BET Surface Area Report...
Page 219: ...Gemini VII Report Examples 239 42828 01 Dec 2012 7 27 BET Surface Area Plot...
Page 220: ...Report Examples Gemini VII 7 28 239 42828 01 Dec 2012 t Plot...
Page 221: ...Gemini VII Report Examples 239 42828 01 Dec 2012 7 29 BJH Adsorption Cumulative Pore Volume...
Page 222: ...Report Examples Gemini VII 7 30 239 42828 01 Dec 2012 BJH Adsorption dV dlog w Pore Volume...
Page 264: ......
Page 266: ......
Page 294: ...Appendix B Gemini VII B 28 239 42828 01 Nov 2013...
Page 364: ...Appendix F Gemini VII F 18 239 42828 01 Dec 2012...
Page 372: ...Gemini VII Smart VacPrep Operator Manual Dec 2013 G 1 G Smart VacPrep Operator Manual...
Page 380: ...Contact Us vi Smart VacPrep Operator Manual...
Page 390: ...2 About the Software 2 4 Smart VacPrep Operator Manual...
Page 424: ...8 Error Messages 8 4 Smart VacPrep Operator Manual...