Optical Profiler – Used To Measure Height Changes

By Author: Vishal Khosla
Total Articles: 19
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Optical profiling is designed to measure surface roughness, finishes and shapes. This is achieved by making sure that adequate light from the surface is back to the material. The device can also be used in the analysis of sawing, polishing and grinding cumulative effects, and wears by calculating the volume of scrapes and voids.

Optical profiler is a measuring instrument used to measure height changes and offers high accurate measurements. Using light wavelength to perform the measurement, the device uses the properties of light wave to evaluate the optical pathway variation between reference surface and the examination surface. A beam of light is dispersed in the profiler. Half of the beam is reflected from the reference mirror while the remaining half is reflected from the test object via microscope's objective focal plane. Constructive interference and destructive interference is created when the beam splitter distance to the reference mirror is equal to the distance of the light splitter to the test surface. It results in rejoining of the split beams with variation in the length of beam light. As a result, interference ...
... fringes are created.

Reference mirror is almost flat to ensure that the optical pathway variation is as a result of changing height in the test side. The digital camera differentiates the focused interference beam. Constructive interference appears lighter while destructive interference appears darker. Optical profiler scans the object vertical. The object causes interference as it moves via the focal plane. Every height level of the test object does not reach optimum focus at the same time. This instrument offers better results than manometer. Applications of this measuring device include: In place where micro-measurement of surface difference is needed.

The instrument is used by several industries including data storage and optics. They are also used on mirror surface completion and surface coarseness, surface texture and curvature rate to measure the volume, radius of curvature and slope of diffraction gratings of binary lenses. Data storage surface metrology focuses on the surface outline of the disk at the edging, the geometry of laser-textured bumps and surface finish roughness. The instrument is the best tool to measure consistency, peak to peak, the grid alignment and bump shape.

Optical profiling is designed to measure surface roughness, finishes and shapes. This is achieved by making sure that adequate light from the surface is back to the material. In high slopes where light is reflected past the material, Optical profiling cannot be used. Optical profiling is the best and accurate tool to measure plastic, glass, metals, paper, paint, epoxies and ink. It is also used in the analysis of sawing, polishing and grinding cumulative effects, and wears by calculating the volume of scrapes and voids.

Many engineering surface measurements uses the instruments for wide step height, in place where three dimensional picture of a surface is required, finding the average heights of various parts such as taking measurement of brittle hollow surface. This measuring tool is the best tool for measurement. It is able to measure very critical shape which may be hard to measure under normal conditions. This tool can be purchased any of the electrical shop. You just need to web search the best shop selling the device at affordable price. In summary, optical profiler is the most accurate and simple instrument to use in most engineering application.

Author of this article is associated with Rtec Instruments, a California based company that deals in high temperature tribometer, white light interferometer, surface profiler, 3D profilometer, atomic force microscope and other instruments.