AbstractThe numerical method of digital simulation has been applied to the rotating disk electrode with optically transparent ring which represents a new electrochemical system, developed recently by Debrodt and Heusler in order to detect directly intermediates of electrochemical reactions. The extinction has been calculated as function of the geometric arrangement of the electrode system and of the rate constant of a first‐order follow‐up reaction. By comparison of calculated working curves with absorption measurements kinetic parameters can be determi