Testing Method of Ndt Wire Rope Tester
There are many testing methods for ndt wire rope tester, including ultrasonic testing, ray testing, acoustic emission testing, eddy current testing, electromagnetic testing, mechanical testing, acoustic testing, current testing, optical testing, vibration testing, etc. Until recent years, electromagnetic testing is the main method in the testing of ndt wire rope tester, and the other non-destructive testing technology is still limited to the laboratory research stage.
In view of LF type defect of local damage, magnetic flux leakage detection principle is adopted, that is, the defect of wire rope is detected by leakage magnetic field at the broken wire of wire rope.
In view of LMA type defect of metal cross-section area loss, the main magnetic detection method is adopted, that is, the change of metal cross-section area of wire rope is detected by measuring the magnetic flux passing through the inside of wire rope.
According to the different working principle of electromagnetic detection method, its magnetization can be divided into AC magnetization, DC magnetization and permanent magnetization. Because of its small size, light weight, convenient use and low detection cost, especially the development and application of new permanent magnet materials in recent years, the advantages of permanent magnet magnetization detection device are more obvious, so a large number of permanent magnet magnetization methods are used in electromagnetic detection method.
The commonly used sensor types are Hall element sensor and induction coil. In practical use, the output signal of Hall sensor is not affected by the moving speed of sensor, and the volume of Hall element is small, which has great advantages in measuring small gap space magnetic field. Therefore, the ndt wire rope tester has been widely used.