Effect of Lift-off to Thickness Inspection by Pulsed Eddy Current
-
摘要: 很多常规方法对设备在线运行状态下的壁厚检测都无能为力。而脉冲涡流具有频谱宽、信号穿透能力强和衰减时间长等优点, 完全适合不拆除保温层在线高温或低温金属的壁厚检测, 成为近年来国际上重点研究的一项高新技术。然而, 实际设备的保温层厚度并不完全一样, 因此相对的提离高度也就不同。为了获知提离对脉冲涡流壁厚检测的影响, 就此进行了试验研究。结果表明, 提离高度与误差之间存在相应的函数关系, 并进行了定量分析, 并得到了对检测结果进行合理修正的办法。Abstract: Commonly conventional techniques are helpless to measure wall thickness of equipment in line. However, with the advantage of wide frequency spectrum, strong penetration and longer attenuation, pulsed eddy current(PEC) is very adaptable to measure wall thickness of metal in high or low temperature without insulation removal. The high-tech of PEC is becoming research focus of the world. As the practical insulation thickness different, so the lift-off between metal and probe is different. Researchers made many trials in order to know how lift-off influences measuring. Finally they found the relationship between lift-off and error, made quantitative analysis, established the formula of correcting data of inspection.
-
Keywords:
- Pulsed eddy current testing /
- Lift-off effect /
- Discrepancy
-
-
[1] 李家伟, 陈积懋.无损检测手册[M].北京: 机械工业出版社, 2002. [2] 任吉林, 林俊明, 高春法.电磁检测[M].北京: 机械工业出版社, 2000. [3] Sophian A, Tian G Y, Talyor D, et al. A feature extraction technique based on principal component analysis for pulse eddy current NDT[J]. NDT & E International, 2003, 36(1): 37-41.
计量
- 文章访问数: 4
- HTML全文浏览量: 1
- PDF下载量: 2
下载:
