Sample introduction system for gas chromatograph

Claim 1

A sample introduction system for gas chromatographs, comprising: a sampler unit having a flow-type filling chamber hermetically sealed from the atmosphere and an exhaust chamber; two connecting passageways communicating said filling chamber with said sample; a passageway connecting said exhaust chamber, for venting to the atmosphere; a sample inlet unit having a sample receiving chamber sealed froM the atmosphere and communicating with a source of carrier gas and a chromatographic column, an overpressure chamber communicating with said carrier gas source and vented to the atmosphere; means for providing a pressure differential between said sample receiving chamber and said overpressure chamber; passages provided with sealing bushings, between said filling chamber and said sample receiving chamber and between said exhaust chamber and said overpressure chamber; a metering element formed as a bent tube with parallel ends pointing in the same direction; exit ports formed in said tube ends; rods connected with said ends of said tube beyond said exit ports, said tube and rods being slidably mounted in said sealing bushings and being capable of reciprocating between two fixed positions so that in one said fixed position of said tube with rods and said exit ports of said tube communicate with the said chambers of said sampler unit, with said chambers of said sample inlet unit being sealed from said chambers of said sampler unit by the outer surfaces of said rods, whereas in the other fixed position said exit ports of said tube communicate with said chambers of said sample inlet unit, with said chambers of said sample inlet unit being sealed from said chambers of said sampler unit by the outer surface of said tube.