[en] A digital signal analysis system which has been used to determine the impedance of electrochemical cells with corroding electrodes is described. The measurement system is based on a Hewlett Packard 9830 Calculator which controls data acquisition on a Biomation Recorder and stores the two channels of digital data on cassette tapes. The data are routinely transmitted, analyzed, and plotted on a time-share CDC 6600 system. Application of the system to dummy cells which simulate the behavior of an electrode revealed that quite accurate results may be obtained for idealized systems. Measurements on copper in 0.1 M HNO₃ gave i/sub corr/ = 4.98 x 10^-6 amps/cm² and a double layer capacitance of 14.1 x 10^-6 farads/cm²