Chinese Journal of Magnetic Resonance ›› 2016, Vol. 33 ›› Issue (1): 66-76.doi: 10.11938/cjmr20160106

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A Single-Sided NMR Sensor: Design and Applications

JI Yong-liang1, CUI Xian-jun2, HOU Xing-zhe1, WU Gao-ling1, WANG Qian1, LI Long1, XU Zheng2   

  1. 1. Electric Power Research Institute, State Grid Chongqing Electric Power Company, Chongqing 401123, China;
    2. State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China
  • Received:2015-03-06 Revised:2016-01-21 Online:2016-03-05 Published:2016-03-05

Abstract:

Single-sided NMR sensors are especially suitable for nondestructive examination of large samples, due to their features such as small size, low cost, and open structure. This paper presents the design and applications of a single-sided NMR sensor with relatively high field uniformity. The uniformity of B0 was estimated to be 338×10-6 in an area of 10 mm×10 mm in the horizontal direction; while there was a constant gradient of 4.6 T/min the vertical direction. According to the distribution of the magnetic field gradient, a signal processing method based on FFT and band-pass filter was proposed to extract NMR signals from a thin layer of the samples. The one-dimensional resolution in the depth direction was about 50 μm. Application experiments are presented, including assessing the aging status of polymer composite insulator, measuring the diffusion coefficient of liquids, and analyzing the withering process of plant leaves. It is concluded that the single-sided NMR sensor developed may have potential applications in many fields.

Key words: single-sided NMR, magnet design, diffusion coefficient, polymer composite insulator

CLC Number: