Laser sensors for metals and rough surfaces

When measuring on shiny metals or machined surfaces that have small micro-machining marks on their surface, using a small laser spot is not recommended. This is because the micro-machined surface features suppress homogenous reflections, resulting in a noisy or unstable measurement signal.

Laser sensors with an oval-shaped laser spot of just a few mm in width, similar to a short ‘laser line’, are recommended for these tasks. Interference caused by surface roughness, defects, indentations or holes are filtered out using the oval-shaped light spot combined with special software algorithms. Furthermore, this type of sensor is suitable for distance measurements on structured surfaces i.e. when the distance to the surface and not the structure itself needs to be measured. The oval-shaped light spot is not affected by the surface structures, enabling continuous, stable measurement values to be generated.