多项式拟合法消除电化学噪声的直流漂移

针对典型的均匀腐蚀与点蚀体系中的噪声数据，研究了采用多项式拟合法消除噪声数据中直流漂移的方法的特点，并对消除前后数据的时域分析和频域分析结果的差异进行了比较．结果表明：采用多项式拟合法可以很好地消除噪声数据中的直流漂移，但是必须注意多项式最高方次的选择，建议通过功率谱密度（PSD）图判断拟合结果的正确性．试验证明：为了避免对低频数据产生过度消除，多项式最高方次不宜过高．消除漂移后，噪声谱、噪声时域统计量和PSD的低频段均发生了明显的变化．

Trend removal in the analysis of electrochemical noise by polynomial fitting

Polynomial fitting was applied to remove the DC trend or drift from the electrochemical noise(EN) data of the general corrosion and pitting corrosion.The characteristics of the method were studied and the differences between the results obtained from the EN data with and without drift removing were compared in the time and frequency domains.The results showed that the polynomial fitting is a good detrending method,but it is very important for users to select the polynomial order and verify the detrending results by the power spectral density(PSD).In order to remove the trend and keep the useful lowfrequency components the authors recommend that lower polynomial orders would be good.After drift removing,the EN spectrum,statistical parameters in time domain,and the lower frequency part of the PSD will be changed obviously.