LASER-ULTRASOUND-BASED CONTROL OF PARTS HAVING SPECULAR REFLECTIVITY BASED ON DETECTION HAVING TWO SENSITIVITY LEVELS

摘要

The laser-ultrasound measurement system according to the invention can be used to simultaneously take two measurements at a single given point on the surface of the structure to be analysed, taken with two different levels of intensity of reflected light. For this purpose, it comprises two measurement paths for measuring the signal reflected by the structure, each path being associated with a specific detector (13 and 23). These two paths are configured and arranged in such a way as to receive different proportions of the reflected light signal. To this end, two secondary light signals, of different intensities, are generated from the signal (33) reflected by the structure. There is therefore one measurement path operating at maximum intensity, and one measurement path operating at attenuated intensity. Therefore, if the signal (33) reflected by the surface (41) of the structure comes from a specular reflection and the measurement path at maximum intensity is saturated, the measurement taken by the measurement path at attenuated intensity is still available.