The Noncontact Portable Electromagnetic Acoustic
A noncontact portable electromagnetic acoustic thickness gage that is equipped with a self-contained power supply, developed on the basis of modern digital technologies, and operated with a new highly efficient magnetic-field concentrator designed using modern magnetic materials is considered. The thickness gage has small dimensions and is lightweight, thereby allowing real-time inspection under field conditions to be carried out. The main advantage of this device is its ability to operate on corroded rough surfaces without using a contact liquid. The device can carry out inspection through significantly thick coatings (up to 1.5 mm). The device was tested at OAO Gazprom and at facilities of the Ministry of China magnets Railways of the Russian Federation. A new EMA transducer that can operate on corroded thin-walled articles is considered. The theoretical concept of EMA excitation is discussed. Examples of 3D diagrams are plotted for ideal single-phase transducers, thus allowing shift amplitudes to be estimated at points of a plane normal to the transducer axis.
Tags: neodymium magnets Electromagnetic Acoustic, magnetic electric Smco magnets