Probing Approaches To Pipeline Detection Based On Pulsed Eddy Current

Pulsed eddy current testing technology is a branch of eddy current nondestructivetesting, because it has instantaneous pulse characteristics, using the pulse response, we canmake sense of some basic characteristics of the material, in addition, useful information inthe frequency domain helps to quantify and determine the location, size, shape of defects,so such the pulsed eddy current detection technology, in recent years, gets more and moreattention and nondestructive testing field especially pipeline detection becomes more andmore widely applied.This topic selects artificial manufacturing small oil pipeline specimen with defects onthe surface as experimental pipeline, using pulse far field eddy current testing principle,which means using far side detection signal, not obvious lift-off effect and containing thecharacteristics of test result from two through wall experiment, by building the hardwarecircuit and designing software to complete the task of designing a detecting system forpulsed eddy current pipeline. Hence this will detect surface defects of pipeline. Detectionsystem hardware design is mainly composed of signal generating circuit, poweramplification circuit, motivate and test coil, and detection signal amplification circuitcomponents. It also applies supporting software such as PROTEL, ANSYS in order todetermine hardware link circuit simulation and parameter. Detection system softwareprogram is completed on the basis of LabVIEW, mainly including software filtering, dataacquisition, and data storage and display, etc.Using the design of the detection system, we are capable of completing the pipelineinspection work, as well as observing and storing the change of the detection data in theupper machine on the surface in accordance with wall thickness, as the test data show:detection system is reflected sensitively near pipeline surface, inspection data with thechange of the defect are very obvious, which shows that the detection system for pipesurface defects has enough detection sensitivity, and can have the relevant inspection workcompleted, which proves the feasibility of the design. Furthermore, we can draw furthercalculation from the data that the degree of wall thickness reduction in different positions is closely connected with the testing data of voltage amplitude and the zero time.