Patent ID: 8518704

Claim:
A monitoring process, comprising: monitoring an attribute of multiple chemical mixtures that are each separately contained within one of multiple chemical vessels in a semiconductor wafer fabrication facility, wherein: said monitoring said attribute is performed via a single sensor, without using a separate sensor for each of the multiple chemical mixtures; each of the multiple chemical vessels is connected to said single sensor by a supply distribution system having a plurality of separate flow paths each configured for selective actuation to transport a respective flow to the single sensor, and by a return distribution system having a plurality of separate return paths each configured for selective actuation to transport a respective flow from the single sensor to a respective one of the chemical vessels or to a drain; and said monitoring comprises: selectively transporting a first sample flow of a first chemical mixture of the multiple chemical mixtures from a first chemical vessel of the multiple chemical vessels to said single sensor via a first flow path selectively actuated from among the plurality of separate flow paths of the supply distribution system; measuring, via said single sensor, a first sample attribute of the first sample flow to produce a first sample attribute value for said attribute; selectively transporting the first sample flow of the first chemical mixture from said single sensor to the first chemical vessel or to the drain via a first return path selectively actuated from among the plurality of separate return paths of the return distribution system; selectively transporting a purge flow to said single sensor via a purge flow path selectively actuated from among the plurality of separate flow paths of the supply distribution system, and selectively transporting the purge flow from said single sensor via a purge return path selectively actuated from among the plurality of separate return paths of the return distribution system to the drain; selectively transporting a second sample flow of a second chemical mixture of the multiple chemical mixtures from a second chemical vessel of the multiple chemical vessels to said single sensor via a second flow path selectively actuated from among the plurality of separate flow paths of the supply distribution system; and measuring, via said single sensor, a second sample attribute of the second sample flow to produce a second sample attribute value for said attribute; wherein the first chemical vessel and the second chemical vessel are separate chemical vessels, and the first flow path and the second flow path are separate flow paths.