| 摘要 |
A gas chromatography system has a chromatography column and a detector with a detector chamber connected to the column outlet. A switching assembly, for selectively alternately filling the detector chamber with carrier gas for a baseline measurement and with effluent for analysis, is connected to the detector. This assembly includes a gas chamber connected to the detector chamber, a source of carrier gas connected to the gas chamber, and apparatus for selectively heating gas in the gas chamber to cause carrier gas to be expelled from the gas chamber to fill the detection chamber for a baseline measurement and for cooling gas in the gas chamber to withdraw the carrier gas from the detection chamber so as to draw effluent from the column outlet to thereby fill the detection chamber for an analytical measurement. The heating apparatus includes a hot wire filament mounted in the gas chamber and electrically controlled for selective heating. |
