A system and process for automatically learning a reliable color-based tracking system is presented. Specifically, a fluid spray bar is coupled to a frame assembly which may be mounted on a CMP system. The inputs signals provided to the second transmission gate mixer are reversed as compared to those provided to the first transmission gate mixer. The invention also includes a method of bonding a first monocrystalline semiconductor substrate construction to a second monocrystalline semiconductor substrate construction, wherein the first construction is doped to a first dopant type, and the second construction is doped to a second dopant type different from the first dopant type. Finally, the temperature of the immersion liquid is changed until the determined imaging property is as close as possible to the target imaging property.