Patent ID: 8118050

Claim:
A system for providing constant flow on-line dilution comprising: a first pumping device configured to pump at a first flow rate; a first fluid introduction line for carrying a first fluid, the first fluid introduction line coupled to the first pumping device for pumping the first fluid at the first flow rate; a second pumping device configured to pump at a second flow rate at least substantially different from the first flow rate; a second fluid introduction line for carrying a second fluid, the second fluid introduction line coupled to the second pumping device for pumping the second fluid at the second flow rate; a flow path selection assembly coupled to the first fluid introduction line and the second fluid introduction line; a mixing assembly for mixing the first fluid, the second fluid and a sample; a plurality of fluid transport lines coupling the flow path selection assembly to the mixing assembly, the plurality of fluid transport lines for transporting the first fluid, the second fluid and the sample to the mixing assembly; a controller coupled to the flow path selection assembly for controlling a flow path selection through the flow path selection assembly; and a sample introduction assembly coupled to one of the plurality of fluid transport lines, the sample introduction assembly for introducing the sample into the one of the plurality of fluid transport lines, the flow path selection through the flow path selection assembly having a first flow path configuration and a second flow path configuration, the first flow path configuration coupling the first fluid introduction line to the one of the plurality of fluid transport lines coupled to the sample introduction assembly and coupling the second fluid introduction line to another one of the plurality of fluid transport lines not coupled to the sample introduction assembly, and the second flow path configuration coupling the second fluid introduction line to the one of the plurality of fluid transport lines coupled to the sample introduction assembly and coupling the first fluid introduction line to another one of the plurality of fluid transport lines not coupled to the sample introduction assembly, the flow path selection assembly further comprising a housing and a valve assembly, the valve assembly comprising a plurality of path connection assemblies for coupling with the first fluid introduction line, the second fluid introduction line and the plurality of fluid transport lines.