What difference between optics, laser and probe measurement method?

Optics and laser belong to non-contact measurement and probe is contact measurement. The advantage of non-contact measurement is high-efficiency, no damage and large working distance. The laser has flatness and height measurement function over optical measurement. But it have requirement to workpiece surface roughness and color difference. Workpiece surface too rough and color difference to large which light can’t reflect, those are not suitable for non-contact measurement.

Probe measurement is contact measurement. In this way, it can get actual value directly and unaffected by roughness and color difference. But the disadvantage of it is low speed and will damage to workpiece surface. Therefore, probe measurement generally used to measure hard workpiece such as mould. It’s not suitable for soft and flexible workpiece.