中文摘要：

随着复合绝缘子挂网运行时间的增加,复合绝缘子的老化日趋严重。为了方便快捷地检测复合绝缘子的老化程度,文中根据复合绝缘子伞裙护套的结构特点,设计了一种U型的便携式低场核磁共振传感器。测量样品为挂网运行不同时间的硅橡胶复合绝缘子,采用CPMG脉冲序列激励,得到样品的CPMG回波衰减数据。对CPMG回波衰减数据进行双指数函数拟合分析,得到硅橡胶伞裙材料的等效横向弛豫时间参数：t2,short和t2,long。实验结果表明,硅橡胶伞裙的t2,long参数与其老化程度有很好的对应关系,具体表现为随着绝缘子老化程度的加剧,横向弛豫时间t2,long逐渐减小。

英文摘要：

With the increasing of the service time of silicone rubber insulators in the power system, the aging problem of the sihcone rubber insulators has been more serious. In order to measure the aging of insulators, and according to the structure of the insulators, we designed a portable nuclear magnetic resonance （NMR）sensor with a Ushape structure. The composite insulators with different service years had been measured, and a Carr-Purcell-Meiboom-Gill（CPMG） sequence was employed as the excitation. The CPMG echo attenuation data of different samples were recorded. The CPMG data were fitted with a bi-exponential function and the effective transverse relaxation time： t2,thort and t2,long were obtained. The experimental results demonstrate that the t2 long parameter has a high correlation with the insulator＇s aging degree： an increase in the aging degree of the insulator clearly results in a decrease of t2,long.