Revision 1 26 9/10/2019
results. It can also cause more air to be introduced into the sample chamber, diluting the
sample gas and producing lower-than-expected results.
• If the system is located in a cold climate, the humidified sample gas passing out of the vent
can freeze, blocking off the flow through the sample system. By using a power vent, the
residence time of the sample gas within the system is reduced, making it less likely that the
moist air will freeze inside the analyzer.
2.8 Sample Conditioning System (Optional)
The sample conditioning system is an optional accessory that filters the sample gas and
lowers it to a pressure suitable for use in the system. A typical sample conditioning system is
seen in Figure 2-14.
Figure 2-14: Typical Sample Conditioning System
The sample conditioning system generally consists of a filter, a pressure regulator to regulate
the sample down to 15 psig, and a valve to switch between calibration and sample gas to
allow the system to be calibrated.
The type of filter is dependent on the nature of the gas and generally has a sample sweep
associated with it. Sample gas is usually taken off the bottom of the regulator to drive the
To Next Page
Loading...
