To understand an ultrasonic cleaner and how it performs cleaning or sonification, it will help to understand the basic principles of ultrasound and understand how they are applied to perform ultrasonic cleaning. Ultrasound is sound waves transmitted at frequencies well beyond the range of natural human hearing. Ultrasonic waves created by piezoelectric transducer at the rate of forty thousand times per second cause cavitation, the mechanism that accomplishes ultrasonic cleaning. The generated energy is powerful but is safe for the parts to be cleaned because the energy is localized at a microscopic scale.

Including a surfactant or wetting agent to the bath will reduce the surface tension of the solution. Reduced surface tension increases cavitation strength. A medium vapor pressure is very conducive to ultrasound action. Low vapor pressure will produce cavitation bubbles that will implode with relatively more force, but the result is fewer bubbles and higher cavitation threshold. Higher vapor pressure is not as effective. Although, more bubbles are created, they collapse less intensely due to smaller internal/external pressure differentials. Lower viscosity promotes better cavitation. Higher densities create intense cavitation with greater implosive force.

Parts or receptacles should never be placed directly onto the bottom of this unit. This can cause unit failure because parts will reflect energy back into the piezoelectric transducer(s). Always maintain at least an inch between the beaker or receptacle and the tank bottom to ensure adequate cavitation.

When the tray or beaker is in place, keep the solution within an inch from the top of the ultrasonic unit. It is not the case that less solution intensifies the activity, in the fluid versus cavitation relationship. Units operate at an optimum efficiency when they are filled to within an inch from the top.

A 5 to 10 minute wait after the activation of the equipment for the fresh solution to degas is necessary. This does not need to be repeated with subsequent usage. Degassing is required after the bath has been freshly filled, only.

If using a basket or tray to lower parts into the solution, a holder of open construction is better. Either an insert tray or a mesh basket that is sufficiently perforated for drainage should be used. This will also permit free access of sound energy to the parts.

Replace the ultrasonic cleaning solution in the ultrasonic cleaner often to increase the ultrasonic cleaning action. Solutions, as with most other chemicals, will become spent over time. Suspended soil particles contaminate the solution, which will settle to the bottom of the tank inhibiting ultrasonic transmission.