A manometer is a device used to measure the pressure of gases or liquids. It typically consists of a U-shaped tube filled with a liquid, such as mercury or water. When pressure is applied to one side of the tube, the liquid level changes, allowing for the measurement of pressure differences. Manometers are commonly used in various applications, including HVAC systems, laboratory experiments, and industrial processes. They can be simple, like a glass tube, or more complex, such as digital manometers that provide precise readings. Understanding how to read a manometer is essential for accurate pressure measurement in many fields.