Controlling chromatograph gas streams - by adjusting relative positioning of supply columns in connector leading to detector

摘要

A stream of test-gas, or of test-material entrained in carrier gas, is discharged from the open end of a first chromatographic sepn. column (10) to enter the first end of a generally T-shaped connector (11), from which a lateral branch leads to a detector (16), possibly with a recorder (17) for identified materials. A pressure conduit (12) laterally joins the connector between the first column entry end (13) and the entry end (14) for a main sepn. column (18), generally axially aligned with the first column (10). The main column is mounted in a hollow sealing block (19), e.g. of graphite or synthetic material, permitting the column to reciprocate along the connector main arm, with the extreme positions of the column outlet extending to both sides of the conduit entry point. In a variation the connector is dome shaped instead of T-shaped, and the connector conduits all enter from one of a common housing. ADVANTAGE - The valve-free assembly permits gas-flow control without pneumatic elements.