A printer controller which renders the bands in a plane of a page to measure the resources required to render each band of the plane. The current source which undertakes limitation in the electrical supply lead to the probes is galvanically separated from the voltage supply of the current source itself. Enhanced eye-mark data is generated for an enhanced eye-mark having an instructive portion and a descriptive portion. This determined value can be converted into weight percent concentration at that time by memory data table.