Analogue systems process analogue signals, which can take any value within a range, for example the output from an LDR or a microphone. An audio amplifier is an example of an analogue system. The amplifier produces an output voltage, which can be any value within the range of its power supply. An analogue meter can display any value within the range available on its scale. However, the precision of readings is limited by our ability to read them. The analogue meter can show any value between 1.2 and 1.3 but we are unable to read the scale more precisely than about half a division.