This Information Applies To: Agilent GC Systems
GC Flame Ionization Detector (FID) Baseline Output stuck at more than 500,000 pA up to 8 million counts.
If the FID interconnect spring is bent, damaged or has bad contact with FID base, it can cause a short circuit in the FID signal circuitry. The consequence is an extremely high baseline signal output.
Cool the detector to ambient temperature, then turn off the GC before proceeding to check condition of FID interconnect spring.
T- 20 Torx screwdriver
5/16- inch wrench
Warning: The oven or detector may be hot enough to cause burns. If the detector is hot, wear gloves to protect your hands.
Caution: To avoid contaminating the FID, wear clean, lint-free gloves when handling the collector assembly.
Caution: Avoid exposure to voltages on the instrument, or damaging the instrument while performing these steps by switching off the instrument before performing this procedure.
Steps to Follow
Disconnect the ignitor cable assembly. See Figure 1
Loosen the ignitor with a wrench as shown in Figure 2.
Turn the nut counterclockwise by hand. Remove the ignitor and copper washer. Place it on a clean cloth.
Remove the three screws that hold the FID collector assembly as shown in Figure 3.
Visually inspect condition of the interconnect spring. Make sure that the interconnect spring is not damaged, bent, or dirty. Otherwise, contact your local Agilent service representative for further advice.
If the collector assembly is properly assembled, the longer part of the collector body must be facing down (see Figure 5).
Power on the GC to check the output.
If signal output remains unusually high, contact your local Agilent service representative for further advice.
Learn how to effectively operate your Agilent Gas Chromatography:
GC-9000-1250s - Agilent Intuvo 9000 GC Flame Ionization Detector (FID) Theory and Operation
GC-7890-2250s - Agilent 7890 Series GC: Flame Ionization Detector (FID) Maintenance and Troubleshooting e-learning courses available from Agilent education