Translations:Adventist Youth Honors Answer Book/Nature/Weather/15/en
Aneroid barometer
The purpose of a barometer is to measure the weight of the atmosphere, or the pressure exerted by the air. An aneroid barometer is similar to a balloon, in that it has a cell filled with air. When the outside air pressure increases, the air pressure inside the cell is also increased. The only way it can do that is by decreasing the volume of the cell - in other words, the outside air pressure squishes the cell. Going back to the balloon analogy, the balloon would get smaller. When the outside air pressure decreases, the air inside the cell follows by decreasing its pressure as well. The only way it can do this is by expanding, taking up more volume, and making the cell containing it larger. In the balloon analogy, the balloon gets larger. An aneroid barometer basically measures the thickness of the cell.
