Which statement regarding an aircraft instrument vacuum system is true?

The correct answer highlights that dry-type vacuum pumps with carbon vanes are indeed very susceptible to damage from solid airborne particles and must take in only filtered air. This specificity is important because these types of pumps function using a mechanism that involves vanes sliding in and out of a rotor. When solid particles enter the system, they can cause wear and tear, leading to inefficiency or failure of the pump. To mitigate this risk, a filtration system is necessary to ensure that only clean, filtered air is introduced into the vacuum pump, thus protecting its internal components and extending overall operational life.

In contrast, wet-type vacuum pumps, which utilize oil for lubrication and sealing, generally perform better in higher humidity conditions and don't have the same susceptibility to solid particle damage because the liquid can trap contaminants. However, this does not mean they inherently outperform dry-type pumps in all scenarios; their design and intended use significantly affect their efficiency.

It's also important to note that pumped vacuum systems do require maintenance. Regular checks and possible replacement of filters, as well as monitoring system performance, are crucial for ensuring reliability and efficiency. Lastly, while vacuum systems may have various applications, their primary purpose is not fuel transfer; instead, they are commonly used for powering instruments and other aircraft systems that