The method includes a step of contacting a surface of a sensing material to a surface of a substrate to form a mutual contact area between at least a portion of the surface of the sensing material and at least a portion of the surface of the substrate. The generated error value is compared to a corresponding error value stored in an error memory, each value in the error memory being calculated from at least two data values stored at predetermined locations in the first memory. The photovoltaic module is selectively coupleable to the docking member. The step of adjusting selects, if possible, an unvoiced frame and discriminates against a transient frame.