A 16-channel computer controlled potentiostat has been designed for use with an amperometnc array for analysis in flowing streams The instrumentation developed to date has been used with both linear and radial flow cell configurations which have been constructed "m-house" Analogue and digital circuits for the independent control of 4 working electrodes have been fabricated, tested and integrated successfully to give an amperometnc array. The design is based on the utilisation of common reference and counter electrodes to reduce the complexity of the electrode arrangement Control of the purpose built instrumentation was effected with a 486-33 personal computer and Analog Devices RTI-815 and RTI-817 data acquisition/control cards, which are responsible for hardware control functions and data acquisition via digital and analogue control lmes. Software for instrumentation control, data display (2- or 3-dimensional formats), on-line and post-run data processmg and storage has been developed usmg the QuickBASIC software environment. The user interface utilises a Wmdows style display to achieve user friendliness with an on-lme help facility Data is stored in a spreadsheet compatible format ( ASCII with column delimiter) to facilitate post-run processmg with standard applications packages such as Microsoft EXCEL The system has been applied to the determination of well characterised electroactive compounds usmg flow-mjection analysis Linearity over the range 10"2- lO'^M has been obtamed with a detection limit of 2x 10'7m (S/N = 3 0) for potassium femcyamde The array has been applied to the simultaneous measurement o f both oxidation and reduction currents of femcyamde and hydroqumone.