| abstract |
In a chemical analysis system a sample liquid is passed through a non-wetting porous membrane from a reservoir of sample liquid to a flowing stream of diluent which is constantly flowing when the sample liquid penetrates the membrane under positive pressure differential from the sample side of the membrane. The pressure differential is suitably obtained both by means for exerting pressure on the sample liquids as for example on a stream of sample liquid on the entry side of the membrane as well as a reduction in pressure on the exit side of the membrane. The passage of the sample liquid through the non-wetting porous membrane requires a minimum liquid entry pressure differential across the membrane to cause enough penetration to give a sample liquid which provides in an analyzed diluent stream a detectable presence of the sample liquid in an analytical detector receiving and measuring the stream. |