When using ultracentrifuges, which statement is true?

When using ultracentrifuges, it is crucial to balance the centrifuge very accurately to ensure safe and effective operation. An unbalanced centrifuge can lead to excessive vibration, which might result in mechanical failure, damage to the rotor, or even injury to personnel. Proper balancing is achieved by ensuring that samples are placed symmetrically opposite each other in the rotor, allowing the centrifuge to spin smoothly without undue stress.

The other statements contain inaccuracies. While rotors are designed for durability and may last a long time with proper care, they do not last forever and can be subject to wear and damage over time. Furthermore, while some rotors may have coatings that resist corrosion, this does not entirely eliminate the risk of corrosion under specific conditions or with certain substances. Therefore, maintaining a balanced system is crucial for operational safety and equipment longevity.