Coupling mechanism of an EMAT
Jian, X., Dixon, S., Edwards, R. S. and Morrison, J. (2006) Coupling mechanism of an EMAT. In: Ultrasonics International (UI 05)/ World Congress on Ultrasonics (WCU 2005), Beijing, PEOPLES R CHINA, AUG 29-SEP 01, 2005. Published in: ULTRASONICS, 44 (Suppl. 1). E653-E656.Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/j.ultras.2006.05.123
Electro- magnetic acoustic transducers ( EMATs) generate ultrasonic waves in metals through an electromagnetic coupling mechanism. A concept for EMAT generation, using a coil alone without a permanent magnet, but with a pulse generator and a sample, is introduced. A simplified equivalent coil circuit is given, and has been validated by experimental measurements. Such an equivalent circuit is useful for excitation current calculations, which have often been neglected in previous publications in this area but have proved to be of great importance in considering the efficiency and frequency characteristics of ultrasonic generation. Due to the coil sample coupling, the equivalent coil inductance is dependent on the electrical conductivity and magnetic permeability of the metal sample, the lift-off, the coil orientation relative to the metal sample and the coil configuration. The use of a coil alone to generate ultrasound has limited applications as a suitable ultrasonic detector must also be used, but where appropriate this type of generation source provides a robust, non- contact and inexpensive means of ultrasonic generation without worrying the permanent magnet attracting ferromagnetic particles that can prevent from practical on- line application of EMATs. (c) 2006 Elsevier B. V. All rights reserved.
|Item Type:||Conference Item (UNSPECIFIED)|
|Subjects:||T Technology > TA Engineering (General). Civil engineering (General)
|Journal or Publication Title:||ULTRASONICS|
|Publisher:||ELSEVIER SCIENCE BV|
|Date:||22 December 2006|
|Number of Pages:||4|
|Title of Event:||Ultrasonics International (UI 05)/ World Congress on Ultrasonics (WCU 2005)|
|Location of Event:||Beijing, PEOPLES R CHINA|
|Date(s) of Event:||AUG 29-SEP 01, 2005|
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