A concentric tube manometer is a type of pressure-measuring device that consists of a tube within a tube. The inner tube is connected to the pressure source, and the outer tube is open to the atmosphere. The pressure of the gas or fluid being measured causes the inner tube to move up or down, and the difference in height between the two tubes is used to measure the pressure.
In contrast, a U-tube manometer consists of a U-shaped tube that is open to the atmosphere at both ends. One end of the tube is connected to the pressure source, and the difference in height between the two sides of the U-shape is used to measure the pressure.
Both concentric tube and U-tube manometers are used to measure the pressure of gases and fluids in a variety of applications, including HVAC systems, air conditioning systems, and hydraulic systems.
One advantage of the concentric tube manometer is that it is more compact and easier to install in tight spaces. It is also less sensitive to temperature changes, as the temperature of the inner tube does not affect the measurement. On the other hand, the U-tube manometer has a longer measurement range and is less sensitive to vibration, which makes it more suitable for use in industrial settings.