2nd Class Power Engineering (2B2) Practice Exam

The primary process utilized in a pilot tube for differential pressure measurement involves both fluid velocity and static pressure. A pilot tube, also known as a Pitot tube, works by measuring the dynamic pressure of a fluid flowing within a pipeline, allowing it to determine the fluid's velocity.

As the fluid flows into the pilot tube, it enters through a small opening that measures the total pressure (which includes both the static and dynamic pressures). The static pressure is also measured through a separate opening on the side of the tube. By calculating the difference between these two pressures, the pilot tube can determine the dynamic pressure, which is directly related to the fluid's velocity.

This combination of measuring both fluid velocity (which affects dynamic pressure) and static pressure is essential for accurately determining flow rates in various applications, making this answer the most appropriate choice for describing the function of a pilot tube.