Aerometers are relatively uncomplicated instruments that are designed to measure the density and weight of a gas or liquid. The design for an aerometer is very simple, with the main body of the device nothing more than a hollow tube. Using a weight and a scale that is included within the body of the aerometer, it is possible to place the device directly into the element to be measured and receive an accurate reading.
The actual use of an aerometer to measure the density of a gas or liquid is easy. A weight is placed in the main tube of the device, where it settles into the bottom of the tube. A scale is found on the upper part of the rod that extends from the tube. The weighted tube is placed in the element that is to be measured. With the use of the scale, it is possible to determine the weight of the liquid or gas with ease. The density is determined by making note of where the scale penetrates the surface of the liquid or gas. Of all the tools currently used in weighing gases, the aerometer is often considered one of the simplest and most accurate options.
Understanding the function of an aerometer can best be achieved by understanding the basic law of Archimedes. Essentially, this means that the upward force of a liquid will equal the mass of the liquid that is displaced. Because the weight within the aerometer is constant, this makes it possible to measure the weight and density of gases based on how deep the device sinks into the element. The same is true with liquids, in that the deeper the aerometer sinks into the liquid, the greater the density and weight.
While the aerometer is helpful in measuring gases, both the weight of gases and the density of a gas, the device is not capable of ascertaining the exact nature of the gas or liquid. However, using the aerometer to measure the density and weight of the element can help identify some traits of the element that can aid researchers in narrowing the possible composition of the element.