INTRODUCTION

Electro-Magnetic Acoustic Transducer (EMAT) is an Ultrasonic Testing (UT) technique that generates sound in the component being inspected rather than the transducer. Because the sound is generated in the part inspected instead of the transducer, EMAT is a completely non-contact technique. This gives it significant advantages over more conventional piezoelectric transducers; although it also has some weaknesses, which can limit its applications.

One of the most common uses of a field EMAT inspection device is for volumetric inspection of in-service piping. This technique can be used to examine equipment such as large diameter header piping at high temperature, transmission lines for hazardous wastes, and natural gas distribution lines.