Ultrasonic Systems for Precise Cleaning Applications
2045 Martin Avenue, Suite 204 Santa Clara, CA 95050

Why Kaijo’s Ultrasonic Cleaners Use Frequency Sweep and Auto Tuning

July 7, 2022

When ultrasonic cleaners operate at the right frequency for a cleaning application, they can deliver superior cleaning performance, but in some cases, the cleaning is uneven because there are dead spots in the cleaning tank. To avoid uneven cleaning, the ultrasonic cleaning system has to make sure the peaks and valleys of the ultrasonic waves in the cleaning bath don’t always strike the part surfaces in the same places. Ultrasonic generators have to include features that ensure even cleaning so that the ultrasonic cleaning systems operate as efficiently as possible.

Ultrasonic Cleaning Systems Need Special Features to Clean Evenly

Ultrasonic generators send a high-frequency signal to ultrasonic transducers, which convert the electric signal to sound waves. The transducers are immersed in the cleaning tank and vibrate to generate the ultrasonic waves in the cleaning solution. As the ultrasonic waves pass through the cleaning solution, the wave troughs are low pressure areas that produce cavitation bubbles. These bubbles burst during the subsequent peak high pressures and generate microscopic but powerful jets that strike part surfaces and dislodge contaminants.

When the ultrasonic waves in the cleaning solution form static patterns, more cavitation bubbles form in some places than in others. The microscopic jets strike some of the part surfaces more intensively and cleaning is uneven.

Kaijo’s ultrasonic cleaning systems help ensure even cleaning by varying the main frequency slightly. The main frequency has to be chosen to deliver quick cleaning without damaging the parts to be cleaned. Kaijo systems use the frequency sweep feature to vary the frequency continuously slightly above and below the main frequency. That disrupts the static pattern of bubbles and makes sure the microscopic jets evenly clean all surfaces of the parts to be cleaned.

Auto Tuning Keeps Cleaning Power Constant when Cleaning Tank Conditions Change

Kaijo’s proprietary auto tuning feature checks how much power is being delivered to the cleaning tank and adjusts the ultrasonic generator signal to keep the power at the desired output level. Conditions in the cleaning tank may vary; the loading of the tank with parts to be cleaned can increase; equipment such as a transducer may have to be replaced, or the cleaning solution temperature and additives may be changed. All these factors can influence the loading of the ultrasonic cleaning system and a higher load without a power increase means less effective cleaning.

The auto tuning feature constantly monitors the system load and adjusts the amplitude of the electric ultrasonic signal from the generator. The ultrasonic waves produced in the cleaning solution increase or decrease in strength in accordance with changes in the signal. The power delivered to the cleaning bath remains constant and the ultrasonic cleaning action stays consistent.

When using Kaijo’s frequency sweep feature, auto tuning delivers constant even cleaning across all the parts of the cleaning bath. Cavitation bubbles are distributed evenly throughout the cleaning solution and their numbers reflect the constant cleaning power delivered to the cleaning tank. Uneven or inconsistent cleaning due to spotty distribution of cavitation bubbles or insufficient power delivery is avoided. Damage to parts due to excessive power in the cleaning tank is eliminated. Frequency sweep with auto tuning ensures optimal cleaning performance, combining rapid removal of contaminants with complete cleaning of all surfaces of the parts in the cleaning tank.

As one of the leading ultrasonic cleaner manufacturers, Kaijo’s extensive experience in ultrasonic technology allows the company to help with the selection of the right primary frequency based on the composition of the parts to be cleaned and the contaminants. With the right primary frequency, frequency sweep and auto tuning, Kaijo’s ultrasonic cleaners deliver unsurpassed cleaning performance with excellent reliability.