easy to carry around
does not contain liquid
TAn aneroid barometer, invented by the French 19th century engineer and inventor Lucien Vidie, uses a small, flexible metal box called an aneroid cell. This aneroid capsule (cell) is made from an alloy of beryllium and copper. The evacuated capsule (or usually more capsules) is prevented from collapsing by a strong spring. Small changes in external air pressure cause the cell to expand or contract. This expansion and contraction drives mechanical levers such that the tiny movements of the capsule are amplified and displayed on the face of the aneroid barometer. Many models include a manually set needle which is used to mark the current measurement so a change can be seen. In addition, the mechanism is made deliberately "stiff" so that tapping the barometer reveals whether the pressure is rising or falling as the pointer moves.he aneroid barometer is more durable and compact, and much easier to read. The only particular advantage of a mercury barometer is that it's a direct measurement -- there's no calibration involved. If you can measure the height of the column above the pool and you know the density of mercury, you have the pressure.
Aneroid barometers have a mechanical adjustment for altitude that allows the equivalent sea level pressure to be read directly and without further adjustment if the instrument is not moved to a different altitude.