An oil-filled transformer monitoring system is provided which calculates an oil temperature of an oil-filled transformer with high precision from a current of the transformer and an ambient temperature. Such solutions may be used for both brush plating and bath plating, and are suitable for use with a variety of plating metals and substrate metals without the need to add plating metal ions to the solution in the form of metal salts, chelates or complexes. The liquid crystal layer covers the common electrode and the pixel electrode. The nozzle may also include a third guide vane or baffle that lacks a curved deflecting part. It also may be implemented on a computer system.