Brooks Instrument 5851EM - Manual (Page 47)

4-9
Brooks ® Models 5965, 5851EM
Section 4 Maintenance
& Troubleshooting
Installation and Operation Manual
X-TMF-5965-5851EM-MFC-eng
Part Number: 541B122AAG
September, 2009
GAS NAME FORMULA SENSOR ORIFICE DENSITY
FACTOR FACTOR (kg/m 3 )
Pentane (n-Pentane) C
5
H
12
0.212 1.605 3.222
Phosgene COCL
2
0.504 1.881 4.418
Phosphine PH
3
0.783 1.100 1.517
Phosphorous Pentafluoride PF
5
0.346 2.109 5.620
Phosphorous Trifluoride PF
3
0.495 1.770 3.906
Propane (same as CH
3
CH
2
CH
3
) C
3
H
8
0.343 1.274 2.008
Propylene (Propene) C
3
H
6
0.401 1.234 1.875
Rhenium Hexafluoride ReF
6
0.230 3.279 13.41
Silane SiH
4
0.625 1.070 1.440
Silicon Tetrachloride SiCL
4
0.310 2.465 7.579
Silicon Tetrafluoride SiF
4
0.395 1.931 4.648
Sulfur Dioxide SO
2
0.728 1.529 2.858
Sulfur Hexafluoride SF
6
0.270 2.348 6.516
Sulfur Tetrafluoride SF
4
0.353 1.957 4.776
Sulfur Trioxide SO
3
0.535 1.691 3.575
Sulfuryl Fluoride SO
2
F
2
0.423 1.931 4.648
Tetrachloromethane CCL
4
0.344 2.345 6.858
Tetrafluoroethylene (TFE) C
2
F
4
0.361 1.905 4.526
Tetrafluorohydrazine N
2
F
4
0.367 1.926 4.624
Trichlorofluoromethane f-11 CCL
3
F 0.374 2.244 6.281
Trichlorosilane SiHCL
3
0.329 2.201 6.038
Trimethyloxyborane (TMB) B(OCH
3
)
3
0.300 1.929 4.638
1,1,2-Trichloro-1,1,2-Triflouroet f-113 C
2
CL
3
F
3
0.231 2.520 7.920
Trimethylamine (CH
3
)
3
N 0.316 1.467 2.639
Tungsten Hexafluoride WF
6
0.227 3.264 13.28
Uranimum Hexafluoride UF
6
0.220 3.548 15.70
Vinyl Bromide C
2
H
3
Br 0.524 1.985 4.772
Vinyl Chloride C
2
H
3
CL 0.542 1.492 2.788
Vinyl Fluoride C
2
H
3
F 0.576 1.281 2.046
Water Vapor H
2
O 0.861 0.802 0.804
Xenon Xe 1.383 2.180 5.851
Table 4-3 Conversion Factors (Nitrogen Base) Continued
Ref. No. J-836D508 Gasdata.doc Vsn. 8.6
Example: The desired gas is 20% Helium (He) and 80% Chlorine (Cl) by
volume. The desired full scale flow rate of the mixture is 20 slpm. Sensor
conversion factor for the mixture is:
Nitrogen equivalent flow = 20/.945 = 21.16 slpm Nitrogen
It is generally accepted that the mass flow rate derived from this equation
is only accurate to ±5%. The sensor conversion factors given in Table 4-5
are calculated based on a gas temperature of 21°C and a pressure of one
atmosphere. The specific heat of most gases is not strongly pressure, and/
or temperature, dependent. However, gas conditions that vary widely from
these reference conditions may cause an additional error due to the
change in specific heat caused by pressure and/or temperature.