Research on visual detection technology using eddy current magnet excitation device

Liu

et al. 2013

AMM

Nondestructive testing (NDT) is becoming more and more important nowadays, visual nondestructive testing (VNDT) such as imaging instead of traditional testing methods becomes popular and highly demanded, which makes it possible to see the internal state of objects visually. The magneto-optic (MO) microscope technology for nondestructive testing is detailedly introduced in this paper, include two different MO imaging system to test the buried subsurface defects in metallic and magnetic specimens.

Section: Figure 5 Basic Schematic Of the Moi Systemmentioning

confidence: 99%

Magneto-Optic Microscope Technology for Nondestructive Testing

Liu

et al. 2013

AMM

“…The polarizer filtered the influence of miscellaneous light, and the magneto-optic (MO) image could be received by CCD after being amplified. Finally, the image was analyzed and processed by the computer [2][3][4].…”

Section: Principles Of Operationmentioning

confidence: 99%

“…The original images contain a lot of noises. To extract the information of defects, an image processing method is designed [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Research on Magnet Excitation and Image Processing Used in Visual Detection

Tian

2011

AMR

A novel visual detection set, which can detect sub-superficial defects in conductive specimens, is presented in this paper. The set has a laser source, a charge coupled device (CCD) camera, and a magnetic excitation. The linear polarized light given off by the laser source is modulated by the superimposition of the magnetic fields induced by the coil and eddy current, and acquired by the CCD. Given the exciting current is known and the eddy current is influenced by the defects, the information of defects can be extracted from the image acquired by CCD. The magnet excitation and image processing are described in detail. Experimental tests have been done and the method presented is proved by the experimental results.

A structural health monitoring method based on magneto-optic imaging technology

Deng

2012 IEEE International Instrumentation and Measurement Technology Conference Proceedings

et al. 2012

A magneto-optic imaging system is presented in this paper to detect invisible and buried subsurface flaws in metallic structural, which can be used to monitor structural health. The resulting power of the MO imaging system is mainly given by the parameters of the MO thin films, the magnetic excitation device and image processing algorithms. In this paper, the choice of the MO thin films, the design of the magnetic excitation device and the development of the image processing approaches are introduced in detail. Experimental tests have been done and the method presented is evaluated by the experimental results.