6-3
Calibration
Where,
P
1
= percentage (%) of gas 1 (by volume)
P
2
= percentage (%) of gas 2 (by volume)
P
n
= percentage (%) of gas n (by volume)
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:
20
1.386
80
0.876
100
Mixture Factor =
= 0.945
+
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 6-1
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.
Summary of Contents for 5866
Page 20: ...3 3 Operation Figure 3 2 Proportional Control Figure 3 3 Integral Control ...
Page 21: ...Brooks Instrument Model 5866 Pressure Controller 3 4 Figure 3 4 P I Control ...
Page 23: ...Brooks Instrument Model 5866 Pressure Controller 4 2 ...
Page 32: ...5 9 Troubleshooting Figure 5 3 Valve Adjusting Spacer Locations ...
Page 34: ...5 11 Troubleshooting Figure 5 4 Valve Adjusting Spacer Locations Normally Open N O Valve ...
Page 43: ...Brooks Instrument Model 5866 Pressure Controller 6 6 ...
Page 45: ...Brooks Instrument Model 5866 Pressure Controller 7 2 Figure 7 1 Model 5866E Parts Drawing ...
Page 47: ...Brooks Instrument Model 5866 Pressure Controller 7 4 Figure 7 2 Model 5866M Parts Drawing ...
Page 48: ...7 5 Parts List Table 7 3 Model 5866M Parts List ...
Page 49: ...Brooks Instrument Model 5866 Pressure Controller 7 6 ...
Page 65: ......