Flame Ionisation Detection (FID)

This is a non-selective technique for measuring total hydrocarbons.  It can be used for methane where no other hydrocarbon species are present or in conjunction with a specially designed catalyst used to oxidise non-methane species contained in the sample.

The flame ionisation detector (FID) 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 usually a short-lived condition with the charged components quickly recombining, however in an electrostatic field 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 the measurement response, or the variation can also be accounted for by calibration using the target gas.

FID Analysers

For gas purity, air separation plant, engine emissions, combustion studies and process plant VOC abatement monitoring.


A reliable, accurate & compliant heated FID analyser for the continuous measurement of VOC emissions.


A compact, portable & accurate heated FID analyser for the discontinuous measurement of VOC emissions.


A rugged, well-proven & flexible heated FID analyser for the discontinuous measurement of VOC emissions.

Choose Signal for your FID analysers

A range of rack-mounted and portable FIDs for accurate, reliable measurement of Total, Methane & Non-Methane Hydrocarbons.

Get in touch to discuss your requirements.