What is a sign that an ultrasonic cleaner is functioning properly when testing with aluminum foil?

The presence of evenly spaced pebbles on the aluminum foil indicates that the ultrasonic cleaner is functioning properly. When aluminum foil is placed in an ultrasonic cleaner, the ultrasonic waves create high-frequency vibrations that generate cavitation bubbles in the cleaning solution. These bubbles collapse and create micro-jets in the solution that can effectively dislodge contaminants from surfaces.

If the foil shows evenly spaced pebbles, it reflects that the ultrasonic cleaner is effectively creating cavitation throughout the cleaning solution. This indicates even energy distribution and appropriate frequency for the cleaning process. The pebbled texture demonstrates that the ultrasonic cleaner is producing the necessary agitation to clean surfaces without overexposing any particular area, which could lead to damage or uneven cleaning.

Other signs, such as the foil appearing completely smooth, would suggest insufficient cavitation and potentially ineffective cleaning. Changes in color or the foil sinking to the bottom do not provide a reliable measure of the functionality of the cleaner, as these outcomes could be influenced by factors unrelated to the machine's performance. Thus, observing evenly spaced pebbles provides the most accurate indication of proper ultrasonic cleaning action.