Handy Septum Size Chart
| Instrument | Septum Diameter | Instrument | Septum Diameter | |
|---|---|---|---|---|
| Agilent | Pye/Unicam | |||
| 5880A, 5890, 6850, 6890, 7890, PTV |
11mm | All Models | 7mm | |
| 5700, 5880 | 9.5/10mm | Shimadzu | ||
| On-Column Injection | 5mm | All Models | Plug | |
| Thermo Scientific | SRI | |||
| TRACE GC | 17mm | All Models | Plug | |
| GCQ w/TRACE, PTV | 17mm | Tracor | ||
| 8000 Series | 17mm | 540 | 11.5mm | |
| Finnigan (TMQ) | 550, 560 | 9.5mm | ||
| GC 9001 | 9.5mm | 220, 222 | 12.7mm | |
| GCQ | 9.5mm | Varian | ||
| QCQ | 9.5mm | Injector Type | ||
| TRACE 2000 | 9.5mm | Packed Column | 9.5/10mm | |
| Gow-Mac | 1078/1079 | 10/11mm | ||
| 6890 Series | 11mm | 1177 | 9mm | |
| All Other Models | 9.5mm | 1075/1077 | 11mm | |
| PerkinElmer | ||||
| Sigma Series | 11mm | |||
| 900, 990 | 11mm | |||
| 8000 Series | 11mm | |||
| Auto SYS, Auto SYS XL | 11mm | |||
Tips for Handling Septa
All septa, regardless of composition, puncturability, or resistance to thermal degradation will fail if they are mishandled. Overtightening a septum nut invariably will reduce septum lifetime by increasing coring/splitting. All septa contain volatile materials (e.g., phthalates) that are released when the septum is heated (septum bleed). Because most GCs are equipped with a septum purge, septum bleed generally will disappear within 30 minutes after installing a new septum and exposing it to normal injector temperatures. All Restek septa are preconditioned and are ready to use without delay.