1. What is a Surface Roughness Tester?

A surface roughness tester (also called a profilometer or roughness gauge) is a precision instrument used to measure the micro‑scale irregularities on the surface of a material.

It works by moving a diamond stylus along the surface, detecting the vertical displacements as the stylus follows the peaks and valleys of the surface profile. The instrument then calculates various roughness parameters (such as Ra, Rz, Rq) according to international standards (e.g., ISO, ANSI).

Main features:

- Contact measurement using a diamond stylus.
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- Can measure multiple roughness parameters: Ra (arithmetical mean deviation), Rz (ten‑point height), Rq (root mean square deviation), etc.
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- High accuracy and good repeatability, suitable for quality control and process optimization.
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- Applicable to machined, ground, and polished surfaces of metals, plastics, ceramics, etc.

2. Typical Application Fields
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