In a roof window with a frame structure and an openable, pane supporting sash structure, the top, bottom and side members of the frame and sash structures are for the major part made as wood profiles, which on the outwards facing sides are covered by covering members of weather-shielding material connected with the wood profiles by means of engagement and securing means. Electromagnetic radiation sources may be positioned adjacent the crystal layer. The semiconductor device also comprises first and second electrodes, wherein at least the first electrodes are located over the well and first dielectric. The other metal implant component has a mounting surface for supporting the bearing. In a second calibration step, the common node is allowed to float, the switched plate of the select primary capacitor is connected to the second reference voltage, the switched plate of the reference capacitor is connected to the first reference voltage, and the voltage on the common node is compared to the first voltage on the comparator reference node.