Industrial Microscopes

Surface Roughness Measurement

About Surface Roughness

How to Define Surface Roughness

Surface roughness indicates the condition of processed surfaces.

Surface conditions are determined by visual appearance and tactile feel and are often described using expressions such as smooth and shiny, matte and textured, matte silver, or mirror finish. The differences in both appearance and texture are derived from the irregularities present on the surface of the object.

Irregularities cause roughness on a surface. Surface roughness is a numerical scale of the surface condition of the shininess (or texture) that is not dependent on visual or tactile sensation. Surface roughness plays a significant role in determining the characteristics of a surface.

Facial irregularities on components and materials are either created intentionally or produced by various factors including the vibration of cutting tools, the bite of the edge used, or the physical properties of the material. Irregularities have diverse sizes and shapes and overlap in numerous layers; the concavities/convexities affect the quality and functionality of the object's surface.

Consequently, the irregularity impacts the performance of the resulting product. In the case of assembly components, the surface feature affects the characteristics of the final product, including friction, durability, operating noise, energy consumption, and air tightness. The surface features also influence the product’s quality, such as a paper product’s ability to hold ink/pigment or varnish.

Why Does Surface Roughness Need to be Measured?

The size and configuration of features have a significant influence on the quality and functionality of processed surfaces and the performance of the final products. Consequently, measuring surface roughness is important to meet high performance standards for end products.

How to Measure Surface Roughness Surface irregularities are measured by classifying the height/depth and intervals of surface features to evaluate their concavity/convexity. The results are then analyzed in accordance with predetermined methods, subject to a calculation based on industrial quantification.* The favorable or adverse influence of surface roughness is determined by the size and shape of the irregularities and the use of the product. The level of roughness must be managed based on the desired quality and performance of the surface. The measurement of the roughness of surfaces and the evaluation of surface roughness is an old concept with numerous established parameters indicating various roughness criteria. The progress of processing technology and the introduction of advanced measurement instruments enable the evaluation of diverse aspects of surface roughness.

Methods to Measure Surface Roughness

Measuring surface roughness of components and industrial products and the qualitative management of the resulting data is increasing with the evolution of nanotechnology and the higher performance demands and smaller size of electronic devices. Conventional stylus roughness gauges and other surface roughness testers designed to acquire height information through mechanical contact with the surface being measured are broadly able to measure surface height and features and the superficial condition of the surfaces. However, the increase of soft samples, such as films, and surface features that are smaller than the tip of the stylus probe have led to the demand for noncontact measurement techniques, from linear measurement to nondestructive, precise area measurement. To meet these nano-level surface roughness measurement demands, laser microscopes have been developed as surface roughness measuring instruments capable of providing an accurate, noncontact 3D surface roughness measurement of the surface features of a sample under ambient conditions.

Learn More about Surface Roughness Measurement > Profile method (line roughness) parameters > Areal method (areal roughness) parameters > Evaluating roughness parameters > Methods of measuring surface roughness > International standarization > Technical terminology glossaries > Essentials of surface roughness evaluation using laser microscopy

Download the Roughness Measurement Guidebook Laser microscopes and roughness measurement Essentials of surface roughness evaluation using laser microscopy Selecting the roughness parameter Explanation of roughness parameters (Profile method, Areal method) Advantages of a laser microscope for surface roughness measurement Download Now

Solutions A Powerful Tool to Elevate Your Roughness Measurement With its advanced 3D laser confocal scanning technology, Olympus’ LEXT OLS5100 3D measuring microscope raises your roughness measurement to a higher level. Quickly scan and detect single-nanometer surface features at ambient conditions to accurately measure the depth and height of irregularities. Use its powerful 3D image stitching to expand the field of view. Improve productivity through the microscope’s streamlined workflow and the efficiency of its noncontact measurements, providing high-resolution, high-precision images with complementary optical information. View Product Details

Noncontact, no damage on specimen No preliminary preparation required. Simply place the sample on the stage and begin measurement.

Acquire roughness information from an entire plane Three types of information can be acquired simultaneously, from an entire plane.

Accurate measurement by capturing fine irregularities The 405 nm / 0.4 μm diameter laser beam scans fine features without distortion.

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