System for measuring longitudinal wave thickness of pulse laser

Abstract

The invention belongs to measurement techniques, relates to a thickness measurement system, and in particular relates to a system for measuring longitudinal wave thickness of a pulse laser, which is applied to thickness measurement of metal materials or non-metal materials. According to the system for measuring the thickness, a beam splitter mirror and a convex lens are arranged on one same light path in sequence; a photodiode is arranged on a reflection light path of the light slitter mirror and is used for receiving the reflection light of the beam splitter mirror; an electric signal output from the photodiode is connected with a receiving end of a signal acquisition card in an electronic computer; another receiving end of the signal acquisition card is connected with the output end of a laser interferometer; the pulse laser and the laser interferometer are arranged on two sides of a tested sample in a centering manner; and the tested sample is arranged on a two-dimensional translation platform. According to the system, the laser interferometer is adopted to detect an ultrasonic longitudinal wave, and the system can be used for on-line measurement and used in a high temperature environment; and by adopting the mode that the pulse laser and the laser interferometer are arranged in a centering manner and the tested sample is arranged on the two-dimensional electric control translation platform, the rapid two-dimensional scanning on the surface of the tested sample through laser is realized.

Description

technical field [0001] The invention belongs to the measurement technology, and relates to a thickness measurement system, in particular to a pulse laser body longitudinal wave measurement system applied to the thickness measurement of metal materials or non-metal materials. Background technique [0002] The method of measuring the thickness of materials or components by ultrasonic method has been developed since the 1940s. The thickness of the material can be measured by multiplying the propagation time of the ultrasonic pulse in the material by the sound velocity in the material. The traditional ultrasonic method uses a piezoelectric transducer as the ultrasonic excitation and receiving device. The ultrasonic frequency excited by this method is low, so the sound pulse is long, so the measurement accuracy is low, and the piezoelectric transducer must be coupled The agent is close to the surface of the material, and it is impossible to realize non-contact measurement and fa...

AI Technical Summary

Problems solved by technology

However, this type of system uses reflected sound pulses. When the sample is thin, the reflected sound pulse and the incident sound pulse will be superimposed, which greatly reduces the measurement accuracy. When the sample is thick or the material attenuation is large, the energy of the reflected sound pulse is very small. It is difficult to be detected, which also limits the scope of application of the method

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