Replica Method (Metrology)

11.7
When the surface is not readily accessibly to the probe, then a replica of surface is made by dampening a piece of cellulose acetate film in acetone to dampen it and pressing it against the surface till it hardens. By this method, 80% fidelity can be obtained. Modern techniques using expoxy and other resins approach 100% fidelity.

Fig. 11.10. Diamond stylus showing typical dimensions.