Thermal Transpiration Correction - Micromeritics Gemini VII 2390a Operator's Manual

Gemini VII

Thermal Transpiration Correction

During data reduction, thermal transpiration correction is applied to the data if the user selected Ther-
mal transpiration correction from the Report Options dialog. Starting with the first collected
pressure, the following calculations are performed until the pressure ratio (PC/P) is greater than or
equal to 0.99.
 
P SD
----------------------------------- -
=
Y

2.33 T

1 +
G Y

---------------------- -
=

1 +
H Y
------------------------------------------------------
=
F
2
  Y  

= 1 –

PC F

where:
P =
SD =
MD =
T =

=

=
G =
H =
T =
ABT
T =
RM
PC =
F,Y, =
239-42828-01 - Dec 2012
2
MD 3

10
1
    
+ +
Y
0.5 
T
   
ABT 
----------- -
–

F P
   
T

RM
equilibrated collected pressure measured by gauge at temp T
inside diameter of sample tube (mm), from the Report Options dialog
thermal transpiration hard sphere diameter of gas (Å), from the Adsorptive
Properties dialog
average temperature [T
Weber's coefficient, 0.033
Weber's coefficient, 0.245
Weber's coefficient, 2.5
Weber's coefficient, 2
analysis bath temperature (K), from the Po and Temperature Options dialog
room temperature (298 K)
corrected equilibrated pressure at temperature T
intermediate values for subsequent calculations
+ T ] / 2 (K)
ABT RM
Appendix C
(mmHg)
RM
(mmHg)
ABT
C-5