simple  ultrasonic  foil  test

You should be testing your ultrasonic cleaner to ensure it is working properly.  At minimum you should check your unit quarterly, preferably monthly while keep a log of when it was tested, pass/fail, when the next test is due.

​Foil test
With the basket out of the ultrasonic unit, fill your unit to the recommended level of water. Fold a piece of aluminum foil in half the width of the unit. Do not touch the bottom of the unit with foil. Run the unit for one minute. You should see pin holes and pock marks.