Abstract: A flow manifold for high purity analyzers is described, in which all flow control valving is positioned downstream of the measurement device. Specifically, this new flow manifold is applied to a high purity moisture analyzer that utilizes a quartz crystal microbalance detector. The proposed flow design eliminates outgassing and contamination from upstream valving, deadlegs in the flow path, and significantly improves instrument response speed. Experimental data is provided to confirm the performance advantage of the new manifold design over existing designs.

Abstract: Apparatus and method for gas analysis in which a sample gas is introduced into a high pressure sample cell through a long narrow holding tube, having a volume greater than the volume of the sample cell; and a second gas which will not interfere with the analysis is introduced into the holding tube behind the sample gas, at a pressure sufficient to force a portion of the sample gas contained in the holding tube into the sample cell so that the pressure of the sample gas in the sample cell is increased. An analysis of the sample gas in the sample cell is then made by a suitable technique, preferably by photometric analysis.