Micromeritics AccuPyc II 1340 - Page 118

Appendix C AccuPyc II 1340
C-2 June 2013
Substituting from equations (1) and (2) into (3):
(4)
or
(5)
then
(6)
Adding and subtracting P
a
in the denominator and rearranging gives
(7)
Dividing by (P
a
- P
2
) in both the numerator and denominator
(8)
or
(9)
Since P
1
, P
2
, and P
a
are expressed in equations (1) through (9) as absolute pressures and equa-
tion (9) is arranged so that P
a
is subtracted from both P
1
and P
2
before use, new P
1g
and P
2g
may be redefined as gauge pressures
(10)
(11)
P
2
V
CELL
V
SAMP
– V
EXP
+ P
1
V
CELL
V
SAMP
–P
a
V
EXP
+=
P
2
P
1
–V
CELL
V
SAMP
– P
a
P
2
–V
EXP
=
V
CELL
V
SAMP
–
P
a
P
2
–
P
2
P
1
–
------------------
V
EXP
=
V
SAMP
– V
CELL
P
a
P
2
–
P
2
P
a
– P
1
P
a
+–
------------------------------------------
V
EXP
+–=
V
SAMP
V
CELL
V
EXP
1–
P
1
P
a
–
P
a
P
2
–
------------------


–
---------------------------------
–=
V
SAMP
V
CELL
V
EXP
P
1
P
a
–
P
2
P
a
–
------------------


1–
----------------------------------
–=
P
1g
P
1
P
a
–=
P
2g
P
2
P
a
–=