Who determines whether something is clean? Or in other words "How much contamination may be left on an object to be cleaned"?
The frequencies used for ultrasonic cleaning range from 20 kilohertz (kHz) to over 500 kHz and even 1 MHz. The most commonly used frequencies for industrial cleaning are those between 25 kHz and 120 kHz. Frequencies above 40 kHz are more commonly used for high precision cleaning, removal of small particles and delicate parts.
Ultrasonic cleaning machines from table model to standing unit can be expanded to a full line with rinse bath tap water, rinse bath demineralized water and dryer.