SevenStar D07-60B, Инструкция по эксплуатации

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9.2 Conversion Factors Instruction
MFC and MFM are standard calibrated by N
2
while it’s out of factory. Other gas calibrations can be approximated
by converting of conversion factors of our instruction. While using other gas operating:
One single gas: The conversion factors could find out in the users specification instruction.
A mixture of two or more gases: Assume there is “n” sorts of gases, could calculate the conversion factors C by the
following formula:
Basic Formula
：
C=0.3106 N /
ρ
(Cp)
ρ
— Density of the gas
Cp — Specific heat of the gas
N — Structure factors of gas-molecule (See Table 6.)
Table 6. Gas-Molecule Composing factors
COMPOSITION EXAMPLE N VALUE
Single atom numerator Ar He 1.01
Double atom numerator CO N
2
1.00
Tree atom numerator CO
2
NO
2
0.94
Multi-atom numerator NH
3
C
4
H
8
0.88
For mixture gases
：
N = N
1
(ω
1
/ω
T
)+N
2
(ω
2
/ω
T
) + ··· + Nn (ω
n
/ω
T
)
Then
：
0.3106 [N
1
(ω
1
/ω
T
)+N
2
(ω
2
/ω
T
) + ··· + Nn (ω
n
/ω
T
)]
C = ————————————————————————
ρ
1
Cp
1
(ω
1
/ωT )+ ρ
2
Cp
2
(ω
2
/ω
T
)+ ··· + ρ
n
Cp
n
(ω
n
/ω
T
)
ω
1
…ω
n
— The flow of single gas
ω
T
— The flow of mixture gas
ρ
1
…ρ
n
— The density of single gas
CP
1
…CP
n
—Specific heat of the single gas
N
1
…N
n
—Structure factors of gas-molecule (See Table 6.)
Attention
1
）
Standard
：
Temperature 273.15K (0 ºC ); Air Pressure
— 101325 Pa (760mm Hg)
2
）
Please feel free to contact us if the request gas conversion factors could not be found in our appendix.