Sample Gas and Plumbing Cautions DF-150E 37
8 Sample Gas and Plumbing
Cautions
Consistent, high performance from your analyzer requires an understanding of
gas delivery systems and their proper installation.
There are several issues to be aware of during the installation and operation of
any gas analyzer.
Contact Servomex for specific sample conditioning recommendations.
8.1 Normal Operating Conditions
Note: Sample pressure and temperature measured at sensor inlet
Physical Parameter Recommended
Range
Normal Operating
Range
Sample Pressure (See note) Atmospheric + (.2 - .5 psig) -2 psig to 2 psig
Sample Flow 1 scfh (0.5 slpm) 1 – 2 scfh (.5 – 1.0 slpm)
Sample Temp (See note) 75F +/- 10F (25C +/- 5C) 40F – 113F (5C – 45C)
Ambient Temp 75F +/- 10F (25C +/- 5C) 45F – 95F (7C – 35C)
Table 5: Normal Operating Conditions
8.2 Condensation/ Liquid Slugs
Like most gas analyzers, the DF series operation will be compromised if there
is condensation in the sensor. If that possibility exists, the gas should be pre-
conditioned. Several techniques are available. If the gas is a hydrocarbon,
maintain the sample from 20°F to 40°F above its dew point. In some
applications, it may be necessary to chill the gas before it enters the analyzer so
that the hydrocarbons can be condensed and removed. In these applications it
is good practice to pitch the lines to allow any minor condensation to drain
away from the analyzer.
Careful attention should be paid to the location of the process sample tap to
avoid the possibility of liquid slugs from entering the analyzer sample line.
Possible process upset and maintenance conditions should be considered in the
decision.