A self-dumping rain gauge including a collection container with value indications for gauging rainfall amounts is disclosed. The method electronically scans a schematic to recognize a plurality of elements visually represented in the schematic, wherein each of the plurality of elements is associated with predefined schematic element visual attributes; and maps each of the plurality of recognized elements to any one of a plurality of saved database elements, based on common visual attributes. The method includes passively collecting transport and network layer header information from packet traffic in a network. Another embodiment determines how long a battery will provide sufficient charge to power a computing device based on profiles of user activity and associated battery drain rates. When the molten metal hardens the inserts are removed. In order to achieve as compact an arrangement as possible, it is proposed in accordance with the invention to provide the generator with means of suspended fixing on a ceiling.