Rain sensor arrangement

• Windows in buildings, and in particular in roof windows, are often electrically operated. This allows for easy operation of windows in remote and inaccessible places. Moreover it allows for a window or a number of windows to be automatically operated, e.g. to open if the temperature, the humidity or other parameter in the building, becomes too high. This then may aid in the control of the climate inside the building. Correspondingly a window may automatically close if e.g. the temperature falls below a desired value or if it starts to rain or snow outside.