It is very important to always observe the quality of cleaning achieved through ultrasonic cleaning. Do not assume that just because an ultrasonic cleaner was used to clean an item, the item is properly cleaned. There are instances when the quality of cleaning achieved is low.
If the quality of cleaning has decreased, it can be due to one or several factors. The factors that should be considered are ultrasonic cleaning solution, cleaning time, temperature, and the ultrasonic cleaner itself. If all the factors aside from the ultrasonic cleaner are right, the cleaner should be tested. The two tests that can be done to check if an ultrasonic cleaner is cavitating properly are foil test and microscope slide test.