This second edition provides comprehensive information on
electromagnetic acoustic transducers (EMATs), from the theory and
physical principles of EMATs to the construction of systems and their
applications to scientific and industrial ultrasonic measurements on
materials. The original version has been complemented with selected
ideas on ultrasonic measurement that have emerged since the first
edition was released.
The book is divided into four parts:
PART I offers a self-contained description of the basic elements of
coupling mechanisms along with the practical designing of EMATs for
various purposes. Several implementations to compensate for EMATs' low
transfer efficiency are provided, along with useful tips on how to make
an EMAT.
PART II describes the principle of electromagnetic acoustic resonance
(EMAR), which makes the most of EMATs' contactless nature and is the
most successful amplification mechanism for precise measurements of
velocity and attenuation.
PART III applies EMAR to studying physical acoustics. New measurements
have emerged with regard to four major subjects: in situ monitoring of
dislocation behavior, determination of anisotropic elastic constants,
pointwise elasticity mapping (RUM), and acoustic nonlinearity evolution.
PART IV deals with a variety of individual issues encountered in
industrial applications, for which the EMATs are believed to be the best
solutions. This is proven by a number of field applications.