| 摘要 |
The disclosure relates to improvements in the art of gas chromatography, and gas chromatographs containing a detector operated on the thermal conductivity principle. In the conventional gas chromatograph, a pair of resistance filaments constitutes an opposite arm of a Wheatstone bridge, and each of two pairs of filaments provides a reference side and a measuring side, respectively, across which a carrier gas can be flowed and the bridge balanced. A moisture-containing sample can be input and transported via carrier gas through a circuit to a substrate filled column and the moisture and other components of the sample separated according to their different affinities for the column substrate. The sample constituents elute from the column in characteristic sequence as elution bands diluted with carrier gas. The column effluent, in such system, can be flowed across the pair of resistance filaments constituting the measuring side of the bridge and the bridge unbalanced to create a bridge-inbalance signal which can be processed as output data indicative of the moisture contained in the sample. The present invention is based on the discovery that a constant and continuous amount of water vapor from an extraneous source can be added as via water vapor addition means to the carrier gas input to the system sufficient to suppress the normal tendency of the moisture contained in the sample to wet and adhere to gas chromatograph surfaces with which the moisture-containing sample is contacted.
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