EMAT & MRT
EMATs (Electro-Magnetic Acoustic Transducers) is recent advances in technology have allowed us to inspect new types of on-stream piping.
EMAT technique that generates the sound in the part inspected instead of the transducer.
In a simplified view, an EMAT can be considered to be a transducer that uses the interaction of a magnetic wave and eddy currents to couple ultrasound into test pieces. Unlike piezoelectric transducers, which generate the ultrasonic wave in a crystal, an EMAT actually generates the ultrasound in the body of the test piece.
- EMATs will work at high temperatures and pass through and under various coatings while scanning at high speeds
- EMATs are less prone to operator error and will produce more repeatable results.
- EMAT’s have the very real advantage of being able to easily generate a variety of ultrasonic wave modes. Besides the familiar longitudinal and SV (shear vertical) waves, EMATs can also generate SH (shear horizontal) waves and Lamb waves.
Among those benefits are the ability to rapidly inspect 100% of in-service and on-stream piping, tanks, pressure vessels and boilers.
Magnetic Wire Rope Testing “MRT”
BECA provide wire rope magnetic inspection in compliance with with wire rope safety bearing capacity checking principle in the international standard (ISO3154), correctly assess the residual bearing capacity and service life of the tested wire rope in-service through quantitative testing to the effective cross-sectional area loss percentage of actual load-bearing metals caused by various internal and external wire breakage, abrasion, fatigue and other damages , providing users with scientific basis for safe use and reasonable replacement in accordance with standards and specifications, and are High-tech guarantees in preventing effectively rope breaking accidents, reasonably reducing the cost of ropes and scientifically improving wire rope operating efficiency.
The MRT consist on moving a device around the wire rope to be inspected . The device consists of a magnetizing system and a magnetic field sensor. The magnetizing system generates a magnetic field within the cable, the presence of wire breakage and internal or external fault generates a local disturbance of the field which is detected by the sensor. There are multiple devices described in part by the standard for ski lifts NF EN 12927-8. These devices have magnetizing systems and sensors which can be different: electromagnet or permanent magnets, parallel or crossed inductor coils, Hall Effect probes, etc. They are applicable to civil engineering cables provided they have been previously validated on them. The most widely used devices today use a magnetizing system made up of permanent magnets and sensors made up of induction coils.
MRT technique can inspect all kinds of wire rope flaws such as internal, external broken wire, abrasion, corrosion, deformation, and fatigue as shown herein below:
Flaw detection rate Repetition rate Accuracy rate