A gas sensor is disclosed comprising an oxygen pump cell having at least one exterior pump electrode and at least one interior pump electrode disposed on opposite sides of a first solid electrolyte layer. The light fixture can be configured in versions suitable for wall illumination, conference room illumination, ceiling illumination, ground surface illumination, and related illumination applications for interior and exterior use. Software running in a control device monitors touchpad regions for user inputs and converts the raw selected parameters on the touchpad into the Hue, Saturation and Intensity information, used in the preferred embodiment to control light fixture color and intensity. A tracking module can construct a level set and geodesic active contours can be determined for the targets. In one embodiment, at least one rod is fixed against rotation.