How does a water manometer function?

A water manometer operates based on the principle of hydrostatic pressure, where gas pressure is exerted on a column of water in a U-shaped tube. When gas enters one side of the U-tube, it pushes down on the water, causing it to rise on the opposite side. The difference in the height of the water columns is a direct indication of the pressure exerted by the gas. This measurable height difference allows for accurate pressure readings without the need for electrical components or mechanical springs.

Using water as the working fluid provides a simple, reliable, and visual means to indicate pressure, making manometers a common choice for measuring gas pressure in many applications, especially in HVAC and commercial kitchen equipment settings. This method of pressure measurement is essential for technicians in understanding the operational status of gas appliances.