Fid Troubleshooting; Change In Sensitivity; Gases - Thermo Scientific TRACE GC Ultra Maintenance And Troubleshooting Manual

Chapter 11
Maintaining a FID

FID Troubleshooting

Change in Sensitivity

The sensitivity of the Flame Ionization Detector depends on the carrier and
detector gases flow rates and to the detector temperature.
The gas flow rates must be set correctly for proper FID operation.

Gases

The gases normally used with FID are reported in Table 11-2.
The carrier gas flow range depends on the type of the gas used and on the type and
diameter of the capillary or packed column installed.
NOTE Make-up gas is not required when a packed column is used.
The recommended range of detector gas flow rates tolerated by the FID are
reported in Table 11-3.
To gain optimum analytical performance from the FID the hydrogen flow rate
should be experimentally optimized, keeping the carrier and air flows constant, to
obtain the maximum signal intensity for the components of interest.
214
Carrier gas
Capillary Columns
Helium
Nitrogen
Hydrogen
Table 11-3. Recommended flow rates for FID
Gas
Hydrogen
Air
Make-up gas
Table 11-2. Gases used for FID
Packed Columns
Helium
Nitrogen
Argon
Flow rate
30 - 50 mL/min
300 - 600 mL/min
10 - 60 mL/min

FID Troubleshooting

Detector Gas Make-up gas Gas
Nitrogen
Hydrogen +
(recommended)
Air
Helium
Maintenance and Troubleshooting Manual