What's the difference between SMIT & WMIT?
Strong Magnetic Inspection Technology(SMIT) is the mainstream of wire rope nondestructive testing technology. It is relatively mature since the early 20th century development. Weak Magnetic Inspection Technology(WMIT), its essence is the use of remanence for testing. Remanence inspection technology is a new development of wire rope detection technology that is need further tracking and application researches.
On the one hand, SMIT applies a constant strong magnetic field to the wire rope, in order to eliminate the interference of the external magnetic field, the defect signal is easily detected. The signal of WMIT is usually relatively weak, its intensity changes with time, the detection signal is often submerged by noise, and results are quite different in different times.
On the other hand, WMIT can only achieve single-function detection, that is to say, only LMA (wire rope metal cross-sectional area) signal can be detected. It can not distinguish the type of damages. SMIT can truly achieve dual function (LMA and LF) detection, it is easy to distinguish between broken wire and abrasion.
Finally, SMIT can detect static magnetic field, the test results are not affected by fluctuations in the speed of wire rope. WMIT can only detect the changes in the magnetic field, the test results would be affected by wire rope speed fluctuations.