The rotating ring‐disk electrode technique has been extended to a splitring design in which the half rings may be maintained at independent potentials. Availability of two detecting surfaces has facilitated studies in anodic dissolution of alloy or pure metal disks where two components or oxidation states can be simultaneously monitored. The construction of the split ring disk and operational amplifier circuitry for control of the three active electrodes (with disk potentiostatic or galvanostatic) are outlined. Applications to the anodic behavior of copper‐zinc alloys in ammoniacal solution are discussed.