Detector Systems

FID and NPD jets

Supply pressure for capillary makeup gas should be set to about 276 kPa (40 psi).

FID and NPD jets

Depending upon the column type to be used, and/or analyses to be performed, exchanging the jet in an FID or NPD may be necessary. Table 7•1lists available jets.

Note: If switching from packed column operation to capillary operation, the jet for capillary use must be installed prior to column installation.

Table 7-1. Available FID / NPD Jets

Part No.

Jet Tip ID (inch)*

Use

 

 

 

18789-80070

0.030

Packed Column Only

 

 

(FID only: Simulated Distillation,

 

 

TCD-to-FIS 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.

For an FID, the 0.011•inchjet maximizes detector sensitivity and must be used with capillary columns; if used with packed columns, flame•out and clogging problems may occur.

For an NPD, exchanging jets is less critical to detector sensitivity: the 0.011•or 0.018•inchjet may be used with either packed or capillary columns. The 0.011•inchjet must be used with capillary columns.

In packed column applications, the 0.011•inchjet may be tried first. The 0.018•inchjet may then be exchanged if problems are encountered. See Chapter 8, Preventive Maintenance, for specific details regarding jet exchange.

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