MKS 246C, Instruction Manual

Page: 60 / 92

Gas Correction Factor Chapter Three: Overview
50
Example:
Calculate the GCF for a gas mixture of argon (gas 1) flowing at 150 sccm and nitrogen (gas 2)
flowing at 50 sccm, where:
Argon (Ar) Nitrogen (N
2
)
a
1
= 150 = 0.75 a
2
= 50 = 0.25
200 200
s
1
= 1.030 s
2
= 1.000
d
1
= 1.782 g/l d
2
= 1.250 g/l
cp
1
= 0.1244 cal/g ° C cp
2
= 0.2485 cal/g ° C
then:
GCF
M
=
(0.3106) [(0.75)(1.030) + (0.25)(1.000)]
(0.75)(1.782)(0.1244) + (0.25)(1.250)(0.2485)
=
(0.3106) [(0.7725) + (0.25)]
(0.1663) + (0.0777)
=
(0.3106) (1.0225)
0.244
=
0.3176
0.244
GCF
M
= 1.302