Free Space - Micromeritics ASAP 2020 Confirm Operator's Manual

Appendix C

Free Space

Free-space volumes are calculated using the following equations:
V
FW
V
FC
V
where:
P
1
P
2
P
3
T
STD
T
RM
T
1
T
2
V
LOW
V
FC
V
FW
V
ABT
T
ABT
202-42811-01 - Mar 2011
V P
LOW 1
----------- -  ----- 1 – 
= T
T P
1 2
V P
LOW 1
----------- -  ----- 1 – 
= T
T P
2 3
V – V
FC FW
----------------------- -
=
ABT
T
ABT
----------
1 –
T
RM
= 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 (273.13 K)
= approximate room temperature (298 K)
= system manifold temperature before dosing helium onto sample (K)
= system manifold temperature after raising Dewar and equilibrating
with helium (K)
= lower 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 correction (cm
= analysis bath temperature (K), from the Po and Temperature Options
dialog
STD
STD
3 )
3
at standard temperature)
3 at standard temperature)
3 at standard temperature)
ASAP 2020 Confirm
C-3