Experimental Study On Gradient Method Buried Pipeline Corrosion Detection

Pipeline transportation is essential in the country’s economic development and people’s growing needs.As we all know,people will become old with age growing,pipelines are gradually into the "mature" with the increasing of serve time,especially buried pipelines.There are different degrees of corrosion,perforation and other defects in tubular body that buried,due to prolonged using.Therefore,it’s not be ignored that periodic test buried pipeline.Periodic testing is aim to guarantee the safety of buried pipeline transportation.Firstly, this paper introduces the principle of magnetic gradient detection,theoretical calculations to magnetic gradient matrix, and theoretical analyses the feasibility of magnetic gradient method that be used to detect buried pipeline;secondly,detection structural of magnetic gradient sensor is designed base on the principle of magnetic gradient method,the use of test methods for structural cross-type sensor to optimize the magnetic gradient selection and gradient sensor error correction;third,we use filtering software low-pass filtering method to signal denoise,in order to reduce environmental impact of the interference signal detection on the test results.On this basis gradient method to detect buried pipeline software is designed;fourth,design and test tube in the laboratory testing,test results show that: in the case of buried depth of less than 1.5m,the method can effective detection of buried pipeline corrosion defects in the trenches,positioning accuracy error of less than 200 mm. Additionally, in Pu yang, Henan, buried in the sand on the depth of field trials for 1m of pipeline,consistent test results and the actual results of the excavation. Test results showed that the indoor and field gradient method of buried pipeline corrosion defect detection possible, using gradient method to detect buried pipeline enrich existing detection techniques.