Teledyne 238 - Thermal conductivity analyzer - Manual (Page 13)

2-5 Teledyne Analytical Instruments
Thermal Conductivity Analyzer Installation 2
The analyzer is not flow sensitive during measurement; i.e., the OUT-
PUT does not vary with the flow, but for maximum accuracy and repeat-
ability, measurements should be made at the same flowrate used when
calibrating the analyzer.
TBE recommends, for lighter-than-air gas backgrounds, setting the
flowmeter to a lower reading for reference and measurement; this will
conserve gas. For example, for hydrogen or helium, set the flowmeter
reading to 0.1 SCFH. A higher reading is recommended for heavier-than-
air gas backgrounds, e.g., for carbon dioxide or argon, set the flowmeter
to 0.4 SCFH.