Preventive Maintenance

Flame ionization detector (FID)

Table 8-1. Available FID/NPD Jets

Part No.

Jet Tip ID (inch)*

Use

18789-80070

0.030

Packed Column Only

 

 

(FID only: Simulated Distillation,

 

 

TCD-to-FID series operation)

18710-20119

0.018

Packed Column

 

 

(Standard, FID and NPD)

19244-80560

0.011

Capillary Column

 

 

(FID and NPD)

 

 

(FID: high sensitivity, packed column)

* Measured at the jet tip.

NOTE: The 0.011-inch jet optimizes performance with capillary columns.

If used with packed columns, FID flame-out may occur with solvent peaks.

Because jet exchange requires disassembling the collector assembly from the detector base, it is also a convenient opportunity to inspect the detector collector and base for contaminating deposits. Proceed to the next section to disassemble the detector, to exchange the jet, and to perform any necessary cleaning.

Cleaning

Both the jet and the collector bore require occasional cleaning to remove deposits (usually consisting of white silica from column bleed, or black, carbonaceous soot). Such deposits reduce sensitivity and cause chromatographic noise and spikes.

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