Sample And Exhausting Tubing Calculations - Honeywell Midas S2 User Manual

2.3 Sample and Exhausting Tubing Calculations

Description of flow rate, maximum pressure, and vacuum at the inlet and exhaust points.
TABLE 2 -1: Inlet sample specifications
Description
Tubing Length, m (ft)
Back pressure at exhaust point
Back pressure at exhaust point with LIT Check Valve
Transport Time (sec), ID 1/8"
Transport Time (sec), ID 3/16"
Flow rate, cc/min.
Tubing OD, mm (in)
Tubing ID, mm (in)
1
Honeywell recommends thick-wall tubing (1/8" ID) for best speed of response. Due to its lower
surface area, thick- wall tubing may require less conditioning than thin-wall tubing.
2
The flow rate is electronically maintained at approximately 500 cc/min and may vary within
acceptable tolerances.
Tubing lengths vary among gases. See the Topic 6.6: Gas Table for recommended lengths.
NOTE: Honeywell recommends the use of Teflon FEP (Fluorinated Ethylene Polymer) tubing to
assure proper sample transport. The properties of Teflon FEP make it the best choice for
transporting sample toxic gases to instruments when compared with the properties of other
similar tubing materials.
Midas S2
1
15
Maximum
30 (100)
-25.4 cm H O (-10 in H
2
-12.7 cm H O (-5 in H
2
25
53
500 (Flow is constant)
6.35 (0.25)
3.18 (0.125)
O)
2
O)
2
2
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