Corrosion monitoring system and monitoring method

The invention provides a monitoring method for a corrosion monitoring system, and aims to solve the problems that in the prior art, a direct current signal is adopted, the signal is changed and insensitive when passing through a crack, in addition, the direct current signal is easily interfered, so that the signal-to-noise ratio is low, and an alternating current signal with a specific frequency can well remove noise and interference and improve the signal-to-noise ratio under the condition that prior knowledge exists. The corrosion monitoring system provided by the invention adopts alternating current with two frequencies for excitation: 1-5Hz (called low frequency) and 100-1000Hz (called high frequency); and internal corrosion and external cracks of the pipeline can be measured simultaneously. 本发明提供了一种腐蚀监测系统用监测方法，现有技术中，采用直流信号，过裂缝时信号会改变，但不灵敏，此外，直流信号容易受到干扰，导致信噪比低，而特定频率的交流信号在已有先验知识的情况下可以较好地去除噪声和干扰，提升信噪比。本发明提供的腐蚀监测系统采用两种频率的交流电流进行激励：1-5Hz(称之为低频)和100-1000Hz(称之为高频)；可同时测得管道的内腐蚀和外裂纹。