A photovoltaic assembly for converting solar radiation to electrical energy is described. A removable gas-permeable catalyst structure with a substrate for example of metal foil is provided in each flow channel in which the synthesis reaction is to occur. At least one of the microchannels has a length extent and has a first section at a first location along the length extent and a second section at a second location along the length extent. An end of the printed circuit board includes electrically conductive contacts that plug into a receptacle to connect the RF coil and traces to external electrical circuitry when the RF coil is in the geometric center. A counter associated with the component is identified and it is determined whether the counter has been reset.