Have you had an ultrasonic cleaner for a long time? Or did you just receive a new one you're not sure of? Would you like to test your machine to see if it still has what it takes? If so, there is a well known test you can do to prove if it does: the foil test! This is a simple test for all ultrasonic machines. It uses aluminium foil to check if the machine still has cavitation strength. Cavitation is the process used in an ultrasonic machine to deeply clean a designated object.
An ultrasonic cleaner is only as good as it's cavitation process. If the machine does not properly clean then it is of no use. The foil test takes to heart the boundaries of an ultrasonic cleaners capabilities. When you run the foil test on your machine, the results will be critical. In most cases you want a test that will show your machine works. In this case, you want to know how well the machine works. This is most important with an ultrasonic cleaner because of it's main use. Which, to put it simply, is to clean efficiently and thoroughly. Not so simply put, its to use the cavitation process to remove unwanted dirt, oil, and other substances from the surface of an object. So, it is important to run this test to make sure your machine can do this.
For this test you do not need any solutions or heat for the machine.
In the end, the foil sheet should look similarly to the one above. There should be no damage above where the water line was and plenty below. The foil should have holes and crinkles fit for a true ultrasonic machine. If it does not, this means your machine is not doing what it is meant to do.