What is an aneroid barometer used for?

An aneroid barometer is specifically designed to measure atmospheric pressure without the use of liquid. Instead, it employs a mechanical system in which changes in air pressure cause the flexible metal capsule, known as an aneroid cell, to expand or contract. This movement is then translated into a readable measurement, usually displayed on a dial. This technology allows for accurate readings of pressure changes in the atmosphere, making aneroid barometers valuable tools in meteorology and other applications where monitoring air pressure is essential.

The other options refer to different instruments or functions that do not pertain to the operation of an aneroid barometer. For example, measuring pressure using water relates to a liquid barometer, while calculating humidity would involve hygrometers, and transmitting gas flow measurements pertains to flowmeters. Thus, the unique functionality of the aneroid barometer in utilizing a mechanical system for pressure measurement distinguishes it from other devices.