Manometer

Manometer

1. A manometer is a U-shape tube filled with some liquid (usually mercury).
2. Manometer is a device used to measure gas pressure in a container.
3. The pressure of the gas is equal to the sum of the atmospheric pressure and pressure due to the column of liquid.

P_gas = P_atm + P_liquid

Note:

There are a few points we need to know when using a manometer

1. Difference in gas pressure at difference level can be ignored.
2. Pressure on the surface of liquid is equal to the gas pressure in contact.
3. Pressure that cause by liquid = hρg.
4. For a given liquid, the pressures at any point of the same level are the same.
5. For different liquid with different density, pressure at two different level will be different.