Descriptions of Profilometer

A profilometer is a measuring instrument used to measure the profile of a surface to quantify its roughness.Calculate critical dimensions such as steps, curvature, flatness from surface topography.While the historical concept of a profilometer is a phonograph-like device that measures a surface as it moves relative to the stylus of a contact profilometer, this concept is changing with the advent of numerous non-contact profilometer technologies.Scanless technology enables the measurement of surface topography in a single camera acquisition, eliminating the need for XYZ scanning.Thus,dynamic changes in terrain are measured in real time.Modern profilometers can measure not only static terrain, but now dynamic terrain as well such systems are known as time-resolved profilometers.

Type

Optical methods include interferometry-based methods such as digital holographic microscopy,vertical scanning interferometry/white light interferometry, phase-shifting interferometry, and differential interference contrast microscopy (Nomarski microscopy); light intensity detection,focal length variation,Focus detection methods such as differential detection,critical angle method, astigmatism method, Foucault method, confocal microscope,etc.;pattern projection methods, such as fringe projection,Fourier profilometry, Moiré fringes, and pattern reflection methods.Contact and pseudo-contact methods include stylus profilometers (mechanical profilers)atomic force microscopy and scanning tunneling microscopy.

Fourier profilometry

Fourier profilometry is a method that uses deformations in periodic patterns to measure profiles.This method uses Fourier analysis (2D Fast Fourier Transform) to determine the local slope on the surface.This allows the x,y,z coordinate system of a surface to be generated from a single image that has been overlaid with a distortion pattern.It is specifically designed to measure the shape of the human cornea for contact lens design.