Aneroid Barometer – Research Paper Example
Aneroid barometer The Aneroid barometer was invented by Lucien Vidie in 1843. The term aneroid means without liquid or without fluid. The aneroid barometer is used to measure air pressure.
The Aneroid barometer is an easily transportable and adaptable instrument which also has the additional advantage of combining accuracy with strength.
Mercury barometers were very accurate in measurement but they were fragile, bulky, complex to transport and were probably toxic which gave rise to the opportunity to find an alternative. It was found by Gottfried Liebnitz in 1700 that the changes in the width of a hollow disc around a vacuum can be employed to measure air pressure. Lucien Vidie found that changes in the width of the capsule can be transferred to a needle in a graduated disc through a number of levers.
How does it work?
The aneroid barometer is effective when it is made of flexible metal box called aneroid cell made of even thickness and is sealed with a proper weld. The capsule is composed of thin copper beryllium alloy of 0.002 in or 0.05mm thickness. The capsule then undergoes electron beam welding and it is place in partial vacuum. The movements of the needle in the dial, as the capsule contracts and expands are very small, therefore, the chains, linkages and levers that magnify the change and direct them to the needle on the dial should be accurately machined.
The Aneroid barometer may have problems due to temperature when the capsule may expand or contract. A well built barometer solves this problem by using a bimetallic strip that corrects pressure before indicating the same in the dial. Altitude compensation is another problem of aneroid barometers. Standard aneroid barometers are designed to operate at 0 to 3000 ft and can be adjusted to any height within the said limits. For height more than 3000 ft, the barometer has to be calibrated accordingly (The Aneroid Barometer).
The Aneroid Barometer is the Choice of Todays Weather Watchers 2006 Available: http://www.home-weather-stations-guide.com/aneroid-barometer.html. Retrieved on February 11, 2010