Surface area measurement by diffusion-limited current

The method and equipment discussed here for measuring the surface area of conductors in the electroplating process is based on the diffusion-limited current method (DIM). "Diffusion limited current" means a current limited by the diffusion rate of cations towards the cathode. In electrodeposition, at a certain level of potential, the overall rate-limiting step is the diffusion of cations towards the cathode. The application of the voltage determines the concentration of electroactive ions at the cathode-electrolyte interface. If this voltage is negative enough, the concentration of ions at the interface is zero. At this moment, the current is limited by the diffusion rate of cations towards the cathode. It has an excellent ability to measure rapidly and precisely the surface area of conductors with very complex shapes, especially for bodies with sharp edges.