Page 87 - Illustrated Pocket Dictionary of Chromatography

FLOW METER 83

determined at the detector exit (detector off) and at the split exit
port (if split injections are made). Accurate measurement and repro-
duction of the flow rate generate reproducible chromatographic
elution profiles.

A bubble meter is a visual means for determining flow rate in GC. The bottom tube
is connected to a by-pass port on the GC to adjust the gas flow/composition cor-
rectly. Note the bubble approximately halfway up the tube. Determining the time
it takes for the bubble to move between volume markings on the tube allows for
the calculation of flow rates.