Which of the following is true when operating an ultrasonic cleaner?

Using a cover on an ultrasonic cleaner is essential for several reasons. First, it helps to contain the sound waves that create the ultrasonic cleaning action, optimizing the cleaning efficiency. If the tank is left uncovered, some of the energy can be lost to the surrounding environment, reducing the effectiveness of the cleaning process. Additionally, a cover can help prevent contamination from dust, debris, or other airborne particles, safeguarding the items being cleaned from recontamination.

Other options present scenarios that do not align with best practices for using ultrasonic cleaners. For instance, while temperature plays a role in the cleaning process, it does not need to remain below freezing; typically, a warmer solution enhances the cleaning action. Operating an ultrasonic cleaner for only one minute is inadequate for most cleaning tasks, as the duration often varies based on the load and the type of contaminants. Lastly, suggesting that ultrasonic cleaners require no maintenance is misleading; regular cleaning and maintenance are crucial for optimal functioning and longevity of the equipment.