In a visual inspection apparatus for visual inspection of an object, a plurality of monochrome images obtained from an object are used to prepare a plurality of computed color images. The input device may be a keypad and the electronic apparatus may be a mobile communications terminal. The system adapted to process the sensor signal, signal from the vehicle’s stoplight and a time delay between changes in the stoplight signal and corresponding changes in the sensor signal to determine the current condition of a brake. Alternatively each respective component may be adjusted in accordance with a scaling factor dependent on the previous data value presented by the corresponding component of next lower carrier frequency, the scaling factor being a ratio between a predetermined value and the said corresponding component, the predetermined value depending on the said previous data value. The majority of incoming data items will fall in the first region and are processed normally. The assemblies are then cooled to ambient temperature at a rate sufficient to avoid precipitation of unwanted metal phases at a rate sufficient to maintain dimensional stability.