the actual and reported. Number of working channels: how many working electrodes can the instrument control. A bipotentiostat is necessary to controlling systems with two working electrodes like a rotating ring-disk electrode. A polypotentiostat may be important for controlling some biological experiments with three or more working electrodes. In conjunction with a Zero Resistance Ammeter per electrode many polarisations can be monitored at the same time in the same cell around the he couple potential. If the Zero Resistance Ammeters have an offsetting ability, then multiple tests can be achieved at the same time in the same test cell around the individual rest potential of each electrode. Such features can be useful for corrosion monitoring of coated electrodes or segmented but otherwise coupled welds. Footprint: potentiostats include small devices of about 20 x 10 x 5 cm weighing well under a kilogram or a simple board that can be installed in a desktop computer. A large bench-top model would be on the order of 50 x 20 x 10 cm and weigh up to or more than 5 kilograms. Interface: can the instrument run independently or must it be slaved to a personal computer. Sweep generator: can the system apply an analogue sweep or does it use a digital staircase generator as an approximation. If it does use a digital staircase then the resolution of the staircase is important. Rotating electrode: can the instrument operate a rotating electrode. This is intrinsic for experiments that require a rotating disk electrode or rotating ring-disk electrode. See also Amperostat Coulometry Electroanalytical method Galvanostat Operational amplifier Polarography Potentiometry Voltammetry References Further reading External links Genady Ragoisha (webmaster), "Potentiodynamic electrochemical impedance spectroscopy (PDEIS)", Physico-Chemical Research Institute, Belarusian State University. A description of the use of a potentiostat in virtual instrumentation for electrochemical experiments. Pierre R. Roberge (Webmaster) "Potentiostat", corrosion-doctors.org Electrochemistry Dictionary. "CheapStat: An Open-Source, “Do-It-Yourself” Potentiostat...", Aaron A. Rowe et al., University of California Santa Barbara Electroanalytical chemistry devices Electronic engineering