What does a pneumatic actuator do?

A pneumatic actuator is designed to convert compressed air into mechanical motion. This process is fundamental in applications where linear or rotary motion is needed to perform work, such as opening a valve, moving a cylinder, or driving machinery. When compressed air is supplied to the actuator, it pushes against a diaphragm or piston, causing it to move and thus create the desired mechanical output.

In contrast, the other choices delineate functions that are not characteristic of a pneumatic actuator. The first option describes the role of a compressor rather than an actuator. The second option pertains to sensors or transducers that detect physical changes and convert them into electrical signals, which is unrelated to the direct motion provided by pneumatic actuators. The fourth option involves monitoring processes, which again is outside the scope of what an actuator does. Thus, the correct understanding of a pneumatic actuator's function is essential for recognizing its application in systems that require the conversion of compressed air into useful mechanical work.