The Potentiostat Research Based On Error Compensation

With the increase of energy demand, the pipeline transportation industry isdeveloping rapidly, by the end of the first half of2012, the national oil and gaspipelines has reached93,000kilometers in length. The country will add74,000kilometers of oil and gas pipelines during the "Twelfth Five-Year Plan" period, ofwhich,45,000km of natural gas pipelines,9,000km of crude oil pipelines, oilproduct pipeline20,000km, with a total investment of about350billion yuan. To beexpected the cumulative mileage will exceed170,000km by the end of2016. Withthe increase of pipeline mileage the safety problem can’t be ignored. According tostatistics, half of the pipeline safety accident was caused by corrosion. It have greatsocial and economic significance to study the method of slowing metal corrosion.Cathodic protection is an important method to slow down the speed of thepipeline corrosion. However, the frequency of accidents is still high in the pipeswhich has been applied cathodic protection, because of the potential gotten frompotentiostat is not the real value. The protective potential measured by theconventional methods is not accurate, which is subject to factors such as IR drop,stray current and polarization uneven.Make the sources of error as the starting point, the research can eliminate theerror of protection potential. Based on the reduce of the measurement error, this papergives a method to compensate the potentiostat control error and proposed an errorcompensation method based on prediction.Finally, this paper designed a potentiostat with automatic measurement andautomatic error compensation function. When this compensation method is put intouse in the industrial field, it proved that the instrument is able to achieve the truepolarization potential control and the potential control accuracy was better than±3mV.