A manometer is a device used to measure pressure, typically in a closed system. It works by balancing the pressure of a fluid in a U-shaped tube against the pressure of the fluid being measured. The difference in height of the fluid in the two arms of the U-tube can then be used to determine the relative pressure.
The formula for determining height from relative pressure using a manometer is h = P/ρg, where h is the height of the fluid in the manometer, P is the pressure being measured, ρ is the density of the fluid, and g is the acceleration due to gravity.
There are several types of manometers, including U-tube manometers, inclined tube manometers, and well-type manometers. Each type has its own advantages and is used for different applications.
The accuracy of a manometer depends on several factors, such as the precision of the fluid used, the design of the manometer, and the skill of the operator. In general, manometers are considered to be a relatively accurate method for measuring pressure.
Manometers are commonly used in various industries, such as HVAC, automotive, and aerospace, to measure pressure in different systems. They are also used in laboratory experiments and in medical devices, such as blood pressure monitors.