A phase-detection interferometric microscope (PDIM) is acquired. This instrument measures vertical heights over a modestly large surface area using the technique of optical phase-measurement interferometry, a fast, non-contact optical technique allowing real-time imaging of variations in surface topology with a resolution of about 0.2nm. Time-resolved PDIM imaging will be used in three different electrochemical experiments: preferential anodic dissolution of layered metal dichalcogenide semiconductors at surface defects; surface morphology of activated glassy carbon electrodes in situ; and oxide growth on polycrystalline metal substrates. The instrument also has potential application to problems in surface chemistry, microelectronics, and polymer science.