In practical applications,pulse eddy current testing technology is affected by outer protective layer of the insulation layer,among which the galvanized steel cladding has a significant impact on the signal.The influence of different protective lay-ers on the pulse eddy current signal was studied,especially the effects of thickness,lift-off and vibration of galvanized iron sheet on the signal;meanwhile,the solutions were put forward.When lift-off was the same,the amplitude of the pulse eddy current signal with galvanized steel cladding was dramatically reduced compared to the signal without cladding.In this case,the detection probe with stronger penetrating ability should be selected and the transmitting current intensity should be increased;when the late signal slope was used as the characteristic value of wall thickness,lift-off has little influence on the calculation of wall thickness.Considering the probe vibration caused by magnetostriction,direct contact between the probe and galvanized steel cladding should be avoided during the detection process.
关键词
脉冲涡流/晚期信号斜率/镀锌铁皮保护层/提离高度
Key words
pulse eddy current/late signal slope/galvanized steel cladding/lift-off
维普
万方数据