基于太赫兹波的聚乙烯管道电熔接头缺陷检测分析

摘要

The THz relfection imaging and TDS (Time Domain Spectroscopy) transmission modes are used to detect the electrofusion joint defects of polyethylene pipe (DN=10mm, including inclusion and delamination). THz time domain waveforms and tomography images with different scanning depth (Z1=3mm,Z2=5mm,Z3=7mm) are obtained. The result indicates that the two-dimensional images from the THz relfecting system clearly reveals the inclusions, hidden defects and mechanical damages of pipeline inwall caused by lfuid scouring process. Besides the thickness of the air lamination in the sample is inspected by the time domain waveforms; the thickness also contribute to calculate the strength of the THz wave emitted from the THz-TDS system providing reference to calibrate the THz-TDS system.%以太赫兹(THz)反射成像技术和THz时域光谱透射技术对公称外径D=10mm聚乙烯电熔接头(包含夹杂、分层等缺陷)进行检测，获得接头在不同扫描纵深（Z1=3mm，Z2=5mm，Z3=7mm）的层析图像和时域波形。结果表明：图像可清晰显示样品的夹杂(金属丝)和埋藏缺陷，且不同纵深的层析图像都揭示了管道内壁因流体冲刷产生的机械损伤位置；对THz时域波形进行分析计算获得样品的分层厚度；以样品分层厚度反推THz波的强度，为THz时域光谱装置校准提供了参考。