In one embodiment, an apparatus includes a touch sensor that includes a mesh of conductive material configured to extend across a display that includes multiple pixels that each include sub-pixels. The water heater includes a water tank for storing water, at least one heating element to heat the stored water, a jacket surrounding at least a portion of the tank, and a control system for controlling the water heater. Thickness-related measurements of the wafer can be obtained during polishing and a thickness profile for the wafer is calculated based on the thickness-related measurements. Each air passageway connects with a different launch port. 9A, and outer line comprising a parallel line H3, H4 separate from the longitudinal centerline of said partition wall by a distance of 32\xd7A, and an arc R3, R4 tangentially connected to said parallel line H3, H4 and said inner wall and having a radius r3, r4, wherein both r3 and r4 are \u2153\xd7A or more, meeting r3+r4=4A. The ribs can isolate each nozzle from the other nozzles, in two ways.