Detailed explanation of the working principle of roughness meter

There are two types of roughness meters: contact roughness meters and non-contact roughness meters.

• Contact roughness meter

The working principle of the contact roughness meter is the stylus scanning method. When the stylus is directly lightly across the surface of the workpiece to be measured, the stylus will produce roughness in the direction perpendicular to the surface of the measured profile due to the undulations of the measured surface contour. Move up and down, amplify the signal through this movement through an electronic device, and then output roughness-related data or graphics through a zero meter or other output device.

SJ325 portable rough rub meter

• Non-contact roughness meter

The non-contact roughness meter is a white light interferometer.

W1 type white light interferometer

White light interferometer is an ultra-precision surface profile measuring instrument developed using the principle of optical interference. The illumination beam is divided into two beams by the semi-reflective and semi-transparent beam splitter, and projected onto the sample surface and the reference mirror surface respectively. The two beams of light reflected from the two surfaces are combined into one beam of light after passing through the beam splitter again, and the imaging system forms two superimposed images on the photosensitive surface of the CCD camera. Since the two beams of light interfere with each other, alternating light and dark interference fringes will be observed on the photosensitive surface of the CCD camera. The brightness of the interference fringe depends on the optical path difference between the two beams of light. The relative height of the measured sample is analyzed based on the brightness of the white light interference fringe and the position where the interference fringe appears.