A geographic information system and method that facilitate the display of user-annotated datasets. A liquid crystal layer is sealed between the couple of substrates with the pixel electrodes formed and the gaps are alternately disposed to form a staggered arrangement between the pair of pixel electrodes. Preferably, a surface portion of the aluminum profile on which an edge portion of the sheet material is to be laminated is further subjected to a local electric discharge treatment by means of a local electric discharge treatment unit. This avoids the need to use complex subtraction procedures normally used to remove the contribution of water from detected absorbance measurements. In an alternative arrangement, the electrode position V2 is replaced by an electrode position Vc on the sternum directly between the standard electrode sites V1 and V2. The oil-filled transformer monitoring system of this invention has an oil temperature calculation device to calculate a transformer oil temperature using measurements from a transformer current measuring device and an ambient temperature measuring device.