How to choose appropriate measurement parameters for roughness profiler?

When measuring with a roughness profiler, selecting appropriate parameters is the key to ensuring accurate and reliable measurement results.

Sampling length

Sampling length is the basic length unit for evaluating roughness parameters. Generally speaking, the sampling length should be selected according to the processing method of the workpiece surface. It is recommended to choose 0.8mm for turning surface, 0.25mm for grinding surface, and 2.5mm for milling surface.

Measuring range

The measurement range is selected based on an estimate of the workpiece surface roughness. If the surface roughness Ra value is between 0.1~0.5μm, it is recommended to choose the measurement range of ±20μm; if the Ra value is between 0.5~2μm, choose the measurement range of ±50μm.

stylus selection

Conventional styli (tip radius 5μm) are suitable for most measurement scenarios. For soft materials or delicate surfaces, choose a stylus with a smaller tip radius. For rough surfaces, choose a stylus with a larger tip radius to extend service life.

Cutoff wavelength

The cutoff wavelength is a filtering parameter used to differentiate between roughness and waviness. Usually, the cut-off wavelength is 0.8mm. For high-precision surfaces, it is recommended to take 0.25mm; for rough surfaces, it is recommended to take 2.5mm.

Measurement speed

It is recommended that the measurement speed be controlled at 0.5mm/s. Too fast a measurement speed may cause the stylus to jump, affecting the measurement results.