An assembly or system is provided for selectively regulating journal bearing lubrication between at least first and second levels in an aircraft engine. Devices are provided comprising a substrate and a semiconductor over a surface of the substrate. In the pixel region, the first electrode is formed in a planar shape and below an insulation film, and the second electrode has a plurality of linear parts which extend linearly and are arranged with respect to each other and is formed above the insulation film. The concentrations of the dyes may be chosen so that a large volume delivery device is calibrated using a spectral feature in the solution with a low absorbance per unit pathlength, while a small volume delivery device is calibrated with the same sample solution but using a different spectral feature with a high absorbance per unit pathlength.