Patent ID: 9182375
Filing Date: 2015-11-10
Classification: G01N

Abstract:
1. A measuring apparatus for metallic microstructures or material properties, comprising: a pulse laser oscillator configured to output a first laser beam; a beam splitter configured to split the output first laser beam into split beams; optical paths configured to propagate light of the split beams split by the beam splitter, respectively, taking different times for light propagation thereof; a condenser configured to superimpose the light of the split beams propagated through the optical paths, respectively, on an identical spot of a measuring material, for irradiation therewith; a laser interferometer configured to irradiate the measuring material with light of a second laser beam, and have light intensity variations resulting from interferences between reference light and light of the second laser beam reflected or scattered from the measuring material, as bases to detect ultrasonic waves energized by the light of the split beams, the ultrasonic waves at least partially overlapping after being transmitted in the measuring material; and a waveform analyzer configured to calculate a metallic microstructure or a material property of the measuring material based on ultrasonic waves detected by the laser interferometer, wherein a difference between light propagation times of two of the split beams that arrive at the measuring material consecutively is Δt, a pulse width of the first laser beam is tp, a constant representing overlap between said ultrasonic waves energized by said two of the split beams that arrive at the measuring material consecutively is a, and a relation Δt<a·tp is satisfied.