When determining the liquid content in liquids, the amount of substance of the liquid is not taken into consideration. For example, a glass of water or a jug of water is different in volume but the density of the water does not change. Since the volume of the liquid varies depending on the temperature, the density determination should be carried out mainly at a temperature between 15-20 degrees. If the density of a substance is mentioned, its density at a constant temperature should be meant.

Mathematically, the mass of a substance is the ratio of its mass to its volume. Density, or eigenvalue, is the mass per unit volume of any substance. The density of one cubic centimeter of water is 1 grams. The density of one centimeter cubic iron is 7.8 grams.

Relative density is relative density. It is usually calculated by taking the ratio of the density of a substance to the density of the water.

Information on the density of foods is important for processes in which separation techniques are used in the food sector. Differences in densities are important in mixing and size reduction processes. Therefore, density and viscosity measurements should be made at regular intervals. Today, food production companies make density and consistency measurements using modern tools and equipment. Densities or extracts of pure substances are constant, but the density of the mixtures is variable.

The density value is characteristic of substances, but it does not only define which substance is known to have a density. Because there may be other substances with the same density value.

Density and relative density determination studies are also carried out in the authorized laboratories within the scope of physical analyzes. During these studies, standards, general test methods and test criteria published by local and foreign organizations are followed.

Diver and swimmer type devices are used for density measurements in liquids. In general, these devices are called aerometers. The basic operating principle of these devices is that the buoyancy force of the liquid is directly proportional to the liquid density. Some of these devices directly show the density of the liquid, while others show different values ​​such as bome, percentage of alcohol and milk density.