The power efficiency of an ultrasonic cleaner is essentially the ratio of the consumed electrical power to the sonic power actually delivered into the cleaning tank’s bath. The higher the power efficiency, the lower the consumed power for a given cleaning application. It is an excellent measure of the ultrasonic units’ cleaning efficiency. Moreover, it is also a good indicator of the overall health of the ultrasonic cleaner, and its periodic measurement is highly recommended. The cleaning efficiency depends strongly on the delivered power levels and the condition of the cleaning liquid.

From a practical standpoint, the importance of maintaining high power efficiencies grows with the size of the ultrasonic cleaner. In smaller units, such as those used for jewelry, dental instruments and prosthetics, the scale and cost of power is not critical. As the scale is increased, the net power consumed increases more or less proportionately. Since even in larger home-scale or lab-scale cleaners the power drawn can be a hundred watts or more, it is important that we do not add too much to our power bill! In industrial-size ultrasonic cleaners, the cost of electrical power consumed heavily influences the operating cost. The high power consumption in industrial applications drives the need for their consistently high power efficiencies.

Ultrasonic cleaners are efficient devices in their usage of electrical power. A properly configured unit can have effective power efficiencies as high as 80-90%, when operated correctly. With respect to electrically powered mechanical devices, whose power efficiencies range from 30-50%, they compare very well. Below we list the most important methods in sustaining high operational power efficiency.

To ensure high power efficiency, operate the units’ transducer-mass system as closely as possible to its natural resonant frequency. Each particular transducer-mass unit has a single natural resonant frequency. In such a cleaner, it is possible to force the transducer-mass unit to oscillate at higher frequencies but this is at the cost of significantly reduced delivered power. This is the reason why sweep frequency variations are limited to