Certified Pulmonary Function Technologist (CPFT) Practice Exam

The device used to measure barometric pressure is the manometer. A manometer measures pressure by balancing a column of liquid against the pressure. In the context of barometric pressure, it often utilizes a mercury or water column to provide a visual representation of the atmospheric pressure.

The U-tube is actually a type of manometer. It is shaped like a "U" and measures the pressure by comparing the heights of liquid in each arm of the tube. While it can be used to measure pressure differences, including barometric pressure, it is more specific in its application than the general term "manometer."

Tachometers are used to measure rotational speed, typically in engines, and have no relation to measuring atmospheric pressure. Hydrometers measure the specific gravity of liquids and are not applicable for pressure measurements. Understanding the functions and applications of these devices highlights the manometer's significance in measuring barometric pressure.