A method for coherent estimation of the traffic-to-pilot energy ratio is presented. One such system utilizes first and second working electrodes to measure additional analyte or non-analyte related signal. A supply portion for an adhesive tape T is disposed in the vicinity of a table 24, and the supplied adhesive tape T is attached to the protective sheet S1. Further, the encapsulated areas of metallization can serve as a self-aligning etch mask.