Preventive Maintenance

Packed column inlet

Packed column inlet

Changing septa

Septum lifetime is dependent upon frequency of use and upon needle quality; burrs, sharp edges, rough surfaces, or a blunt end on the needle decreases septum lifetime.

A leaking septum is evidenced by longer retention times, loss of response, and/or loss of column head pressure as well as degradation in detector signal quality (the signal becoming increasingly noisy). Where the instrument is used on a regular basis, daily septum replacement is recommended.

Figure 8-2

Septum

Septum Retainer

Nut

 

Packed Column Inlet, Replacing the Septum

 

Turn off the detector (particularly a TCD or NPD!) before interrupting

Caution

 

column flow.

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