Brooks Instrument 5851EM - Manual (Page 54)

4-16
Brooks ® Models 5965, 5851EM
Section 4 Maintenance
& Troubleshooting Installation and Operation Manual
X-TMF-5965-5851EM-MFC-eng
Part Number: 541B122AAG
September, 2009
In the example, the restrictor should be sized for a 60.1 slpm flow rate.
Note: If the calculated flow rate is such that two different size restrictors
could be used, always select the larger size.
If a mixture of two or more gases is being used, the restrictor selection
must be based on a Nitrogen equivalent flow rate of the mixture.
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. In this example
a Size 4 Wire Mesh Assembly would be selected.
Table 4-4 Model 5965/5851EM Standard Restrictors
Range Restrictor
slpm Nitrogen Element
Equivalent Flow* Combination Part Number
4.6 to 15 1-40 micron (1 inch) S613E666BMG
15 to 26 1-40 micron S613E657BMG
26 to 42 2-40 micron S613E658BMG
42 to 60 3-40 micron S613E659BMG
60 to 79 2-40 micron/1-60 micron S613E661BMG
79 to 93 1-40 micron/2-60 micron S613E663BMG
93 to 130 3-60 micron S613E655BMG
130 to 400 3-60 micron S613E662BMG
400 to 600 3-100 micron S613E656BMG
* Based on 0°C Standard Reference Temperature
NOTE: If the nitrogen equivalent flow is between two sizes, select the
larger size.