Design Of Portable Multi-channel Electrochemical Noise Testing System

In China, Nuclear power will play an important role in energy supply in future. However, there is no effective method for online corrosion monitoring at present. Electrochemical noise technology(EN),which is considered as an intrusive and direct technique to m onitor c orrosion pr ocesses, i s i deal f or corrosion m onitoring. Data acquisition o f mu lti-channel i s n eeded f or E N t est, b ecause o ne el ectrochemical sensor can only monitor a small area. Therefore, it is of great significance to develop multi-channel EN test instrumentation for nuclear power.In the paper, according to the requirement of EN test and characteristics of EN signal, a portable multi-channel EN testing system is developed. Modular instruments cRIO is used as the core of the system. Because of the low level of the EN signal, a great effect is made on circuit design in signal conditioning modular. 10pA in current accuracy an d 1 0μV in potential accuracy i s r eached. A r ange ch anging s ystem i s developed to resolve the problem caused by high dynamic range of current signal. With help of the range changing system, system is able to measure current signal ranging from 10pA to 10mA. A channel switching module is also designed. With the module’s help, the system could collect data from even more sensor.Both automatic and non-automatic soft is developed for range changing system. EN test soft for long time monitor and short time test is also programmed. For EN data interpretation, An signal processing soft which include most EN analysis method is achieved.Several EN test on c arbonize is carried out in the laboratory with contrast of electrochemical workstation VersaSTAT 4. The result indicates that the measurement is correct and system is capable of achieving EN test of multi-channel.