How Does Lasercheck Technology Work?

When laser light reflects from a smooth mirror a single spot of laser light will reflect from it and strike a target. This is referred to as specular reflection.

When laser light reflects from a machined surface with roughness a diffuse pattern of laser light will reflect from it and strike a target. The specular reflection will be dimmer or lost all together in the diffuse light. As a surface gets rougher the reflection gets more diffuse.

Machining operations generate roughness patterns with a 3D microstructure (example: sandblasting) or 2D microstructure (example: directional grinding). A 2D or 3D pattern of diffuse laser reflection will reflect depending on the roughness pattern on the surface.

The schematic shows the layout of the laser, the beam and the detectors in the Lasercheck® model 6212 surface roughness gage. The system pulses a visible laser onto a surface. Multiple detectors inside the head measure multiple angles of diffusely-scattered laser light as well as the specular reflection. Software analyzes the specular and diffuse reflected laser light patterns to calculate surface roughness.