Oil-Tank Weld Detection Using EMAT

Abstract

Tanks are typically used for the storage of oil by the petrochemical industry, and the storage quality is largely determined by the safety of the equipment. Recently, Electromagnetic Acoustic Transducer (EMAT) technology has been the focus of many non-destructive examinations, as EMATs can generate elastic waves without contact, thereby making it easy to carry out the process of detection. The Shear Horizontal (SH)-guided waves that are generated by an EMAT are modeled in a plate made of ferromagnetic material, and this is of particular interest regarding the testing of welded structures. This paper provides an EMAT-sensor design that can be used to find cracks in the welds of a tank whereby the need for people to climb onto the tank is removed; furthermore, regarding cases where the amplitude signal of the SH-wave EMATs is too low, a simulation is used in this paper to propose a method that improves the transduction efficiency.