Definition - What does Acoustic Wave mean?
An acoustic wave refers to a longitudinal dispersion of pressure pulses of material displacement. This material could be a gas, a liquid or a solid. In metallic solids this wave is observed as a sequence of compression and expansion, making it ideal for examining corrosion rates on the metal's surface.
Corrosionpedia explains Acoustic Wave
The concept of acoustic waves is used to examine corrosion rates on metallic surfaces through the use of corrosion sensors. These sensors monitor corrosion by using two sets of digital transducers that are attached to the surface to be examined. An AC electrical signal is passed through them. The signal generates an acoustic wave. The faster the wave travels from one transducer to the other, the lower the corrosion rate in the substrate metal and vice versa.
The experiment may be carried out in a vacuum or a controlled environment to minimize variations caused by ambient conditions such as temperature and pressure. However, for real-world industrial applications, it is best to conduct the inspection under normal operating conditions.