What is EMAT testing?
What is EMAT testing?
EMAT is a non-destructive testing technology that has applications in a wide range of industrial sectors. EMAT is generally used to assess the condition of manufactured objects and the technology is particularly effective for detection of stress corrosion cracking and disbonded coating.
What is EMAT in marine engineering?
EMAT – Electromagnetic Acoustic Transducer for the contactless generation of ultrasonic waves. An EMAT comprises a magnet and an electrical coil (see the Figure).
What is EMAT pipeline?
3.0 CORROSION DETECTION IN PIPELINE BY EMAT 3.1. BASIC PRINCIPLE OF EMAT. EMAT- Known as “ Electro-Magnetic Acoustic Transducer” is considered to be a transducer that uses the interaction of a magnetic wave and eddy current to transmit ultrasound in the test pieces.
What is the working principle of electromagnetic acoustic transducer?
EMATs works on the principle of the Lorentz force, as explained in Figure 2. To generate a Lorentz force, the material needs to be conducting so as to support an eddy current. For example, in the case of PVC pipes, EMATs cannot directly generate ultrasound from it.
Which can be used in electromagnetic acoustic transducer testing?
As an ultrasonic testing (UT) method, EMAT has all the advantages of UT compared to other NDT methods. Just like piezoelectric UT probes, EMAT probes can be used in pulse-echo, pitch-catch, and through-transmission configurations.
What is a acoustic transducer?
A device, such as an underwater hydrophone, that converts acoustic energy into electromagnetic energy; or a device, such as an acoustic source, that converts electromagnetic energy into acoustic energy.
What is the normal frequency range for the ultrasonic testing?
Most ultrasonic testing is available within 400 kHz to 25 MHz. These vibrations are beyond the audible range and propagate in the test material as waves of particle vibrations. Sound beams of all frequencies can penetrate fine-grained material without difficulty.
How is a transducer measured?
Consider Minimum Transducer Supply Voltage 1. Use Ohms Law to calculate the voltage drop across the resistor. 2. Subtract the voltage drop from the datalogger’s power supply voltage to determine the amount of voltage left to power the transducer (Kirchoff’s Voltage Law).
What is EMAT (electro magnetic acoustic testing)?
EMAT or Electro Magnetic Acoustic Transducer is an Ultrasonic Testing (UT) technique that generates the sound in the part inspected instead of the transducer. An EMAT induces ultrasonic waves into a test object with two interacting magnetic fields.
How does EMAT work?
Electro-Magnetic Acoustic Transducer (EMAT) is an ultrasonic Non Destructive Testing (NDT) which works without contact or couplant. The sound is directly generated within the material adjacent to the transducer.
What is an EMAT inspection?
Our EMAT inspection method is effectively creating and using ultrasound for the detection of cracks/stress corrosion cracking without the need for a liquid couplant. A secondary benefit of the EMAT technology is that it may detect disbonded coating.
How is ultrasound generated with an EMAT?
How is ultrasound generated with an EMAT? An EMAT or Electro Magnetic Acoustic Transducer consists of a magnet and a coil of wire and relies on electro-magnetic acoustic interaction for elastic wave generation (ultrasound).