We need to know that ultrasonic cleaning technology is based on sound waves. Any sound wave frequency, more than 18 kHz, is considered ultrasonic. Usually, the frequency in the ultrasonic cleaning tank is between 20 kHz and 80 kHz. A sound wave occurs when a single or repetitive displacement is created by an acoustic conductive medium such as vibrating motion. When a high amplitude of sound waves is placed in the liquid, a negative pressure is created. If it is continuous, this negative pressure will eventually increase to the point that the fluid will break down. During the ultrasonic process, millions of cavities are created in this way. Cavity oscillates as a sound wave passes through the liquid. This, in turn, increases the positive pressure, which makes the cavity bubbles unstable. Eventually, the positive pressure causes the cavitation bubbles to collapse violently, leading to an explosion, and shock waves radiate from the collapsed “bubbles.” This collapse and explosion of millions of cavity bubbles throughout the ultrasonic tank is the basis of ultrasonic cleaning technology.