An instrument is provided for a motor vehicle that includes, but is limited to a display area and a housing, which surrounds the display area. A specimen is placed onto a known background within the field of view of an image sensor having multiple pixels. The invoked action is dependent on the individual mesh entry or the zone in which the write operation was detected. A tip is in contact with the reservoir and one end of the tip acts as a wick to draw the solution from the reservoir to the tip, and the other end of the tip is configured to apply the solution to a surface when that end of the tip is placed in contact with the surface. The gain blocks may be partitioned into steps that represent particular gain values within a range associated with the gain block.