Air Pressure- Air pressure refers to the weight of the Earth’s atmosphere that pressing down on

everything at the surface.

- Air pressure also known as atmospheric pressure.

- The average air pressure at sea level is 1,013 x 105 Pa, that referred as 1 atmosphere.

- We could survive on the earth, from this atmosphere pressure, because the natural

pressure within our bodies is also about 1 atmosphere. It helps us to balance out the

atmospheric pressure.

- We may suffer injuries or altitude sickness if there is a great amount of atmospheric

pressure.

- We can measure air pressure by using barometer. The most common barometers to be

used are mercury barometer and aneroid barometer.

- The right picture showing us that atmospheric pressure

acts on the surface of the mercury in through. The

pressure on the surface is equal to the atmospheric

pressure.

- By measurement finding, the maximum height of mercury

is found to be 760 mm. above that; there will be just

vacuum space.

- To find pressure on the existing height in the liquid is by

applying this formula; height x density of water x gravity

(hpg)

- Manometer is used to measure differences in pressure of gasses

or liquid.

- It consists of U-tube shape column, contain of liquid (mercury, water,

or oil). The height differences will help us to measure the pressure

difference between the two sides.

- To calculate the atmospheric pressure of gas supply:

Original atmospheric pressure (760 mm) +hpg