Quantity Adsorbed Calculations; Free Space; Measured - Micromeritics Gemini VII 2390a Operator's Manual

Appendix C
P =
rel
I
P =
I

Quantity Adsorbed Calculations

Free Space

Measured

Measured free-space volumes are calculated using the following equations:
V
MAN
------------- -
=
V
FW
T
MAN
=
V V
FC FW
=
V
BATH
where:
P =
1
P =
2
P =
3
T =
STD
T =
AMB
T =
MAN
V =
MAN
V =
FC
V =
FW
V =
BATH
T
=
BATH
C-2
relative pressure for the I
absolute pressure for the I
P
1
 
----- - 1 –
T
STD
P
2
P
 
2
----- -
 
P
3
–
V V
FC FW
------------------------- -
T
BATH
-------------- -
1 –
T
AMB
system manifold pressure before dosing helium onto sample (mmHg)
system manifold pressure after dosing helium onto sample (mmHg)
sample pressure after raising Dewar and equilibrating with helium (mmHg)
standard temperature (273.15 K)
approximate room temperature (298 K)
system manifold temperature before dosing helium onto sample (K)
manifold volume (cm
volume of free space, cold (cm
volume of free space, warm (cm
portion of cold free space at analysis bath temperature: used in non-ideality
3
correction (cm at standard temperature)
analysis bath temperature (K)
th
data point (mmHg)
th
data point, taken at equilibrium (mmHg)
3
)
3
at standard temperature)
3
at standard temperature)
Gemini VII
239-42828-01 - Dec 2012