Laser synchronous scanning imaging trace gas detection method and system

Abstract

The invention relates to an infrared thermal wave imaging nondestructive testing method. High power laser beams are adopted to conduct fast scanning on the surface of a sample through a laser beam deflection device, and meanwhile an image acquisition child window of a thermal imager is arranged to dynamically tail after movement of the laser beams. In a series of thermal wave images collected by the thermal imager, different delays exist between thermal wave signals and thermal excitation of each pixel in each frame of image. The thermal wave images after delay quantity amending and numerical treatment can be used for analyzing internal defects of the sample.

Description

technical field [0001] The invention relates to a trace gas leakage imaging detection technology, which uses a laser beam near the absorption spectrum of the trace gas to scan the measured area, and uses a camera to perform imaging, and the scanning frequency of the laser is synchronized with the camera. The invention can be used for quickly locating gas leakage, and belongs to the technical field of laser imaging detection. Background technique [0002] Laser imaging gas leak detection technology provides a favorable tool for online detection in many industrial fields, such as sulfur hexafluoride laser imaging used in power systems The imaging method effectively finds the leakage point of sulfur hexafluoride electrical equipment and can accurately locate it. This technology can effectively reduce equipment outage time, reduce maintenance costs, improve the reliability of substation equipment, protect personnel safety, reduce air pollution, and has obvious economic and soci...

AI Technical Summary

Problems solved by technology

[0004] However, there are many defects in the products based on the existing technology on the market, the most important is that the detection sensitivity is not high enough, which is mainly limited by the power of the laser. Considering the portability and equipment cost, the laser usually cannot be selected with a large volume and weight. Therefore, the output power is limited, and the optical power density is reduced to a very low level after beam expansion

At the same time, after the laser beam is expanded, due to the beam quality, the error of the optical device, and the coherence of the laser, the spot after the beam expansion is uneven, which affects the quality and stability of the image, and often results in partial images that cannot be detected. It also greatly affects the detection sensitivity

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