Plastic Drift Tubes

PTFE is a poor conductor of heat, so the application of heat to a drift tube made from PTFE must be made gradually or localized overheating may occur with melting or decomposition of the plastic. However, the cost and convenience of machining PTFE makes this material attractive for drift tubes even when operated at temperatures as high as 250°C. 

The same considerations used for insulators and conductors described in the previous sections are applicable to miscellaneous items such as tubing, gaskets, seals, and specialized materials such as adhesives and shells. In low-temperature drift tubes with handheld analyzers, unions for tubing and pump seals and other connections are made using plastics. In research-grade analyzers, connections are usually made with pipe-pipe compression unions or silver-soldered connections. However, material consideration may not be ignored for other parts of a drift tube since even small sources of contamination can render ultrasensitive analyzers, such as IMS drift tubes, unworkable. 

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