Flame Ionisation Detection

Flame Ionisation Detectors (FIDs)

Flame ionization detector - how it worksThe flame ionisation detector is a highly sensitive but non-selective sensor for measuring hydrocarbons.  It uses a simple principle where a flame strips hydrogen atoms from the hydrocarbon molecule, forming carbon radicals and electrons.  This is ordinarily a short-lived condition with the charged components quickly recombining, however in an electrostatic field the oppositely charged components can be driven towards electrodes.  This creates an effective current within the flame, which is proportional to the number of molecules of hydrocarbon present.
The molecular arrangement has an effect on the ionisation mechanism within the flame and therefore the response of the analyser.  A response factor is used to correct this measurement response, or the variation can also be accounted for by calibration using the target gas.

Click here for the Series IV SOLAR fixed FID analysers

Click here for the 3010 MINIFID portable FID analysers