动态直流杂散电流干扰下试片断电法影响因素

Influence Factors of Coupon Instant-Off Testing Method under Dynamic DC Stray Current Interference

通过现场试验研究了试片埋设时间、断电延迟时间、试片埋设深度、外部干扰电场以及参比电极位置等因素对试片断电法测试结果的影响,通过对比不同条件下的测试结果,获得不同因素的影响规律。结果表明:试片的裸露面积越大,达到稳定极化状态所需的时间越长,浅埋试片需要更长的时间才能达到稳定的极化状态;对于试片瞬时断电电位的测试,应设置合理的断电延迟时间;在当前试验条件下,试片极化稳定所需要的时间最长为25 h,150 ms的断电延迟时间是合理的;土壤中流动的电流会在试片和参比电极之间产生地电位梯度,影响试片断电电位的正确读数,可以通过缩小试片和参比电极之间的距离来消减外电场产生的误差。

Through field test,the influence of factors such as test piece embedding time,instant-off delay time,coupon buried depth,external interference electric field and reference electrode position on the test results of coupon instant-off method was studied.By comparing the test results under different conditions,the influence laws of different factors were obtained.The results showed that the larger the exposed area of the coupon,the longer it took to reach a stable polarization state,and the longer the shallow buried coupon took to reach a stable polarization state.For the test of the instantaneous instant-off potential of the coupon,a reasonable instant-off delay time should be set.Under the current test conditions,the longest time required for the polarization stability of the coupon was 25 h,and the instant-off delay time of 150 ms was reasonable.The current flowing in the soil would generate a ground potential gradient between the coupon and the reference electrode,which would affect the correct reading of the instant-off potential of the coupon.The error caused by the external electric field could be reduced by reducing the distance between the coupon and the reference electrode.