The Rdc (Wdc, Pdc) surface texture parameter is the Material Ratio Height Difference. It’s a way of looking at a particular zone of roughness, or waviness, or primary data. The dc parameters are based on the material ratio curve which helps us describe the peak, core, and valley regions of a surface texture.
Learn more about surface texture parameters in our Texture Parameter Video library: https://digitalmetrology.com/texture-parameters/