Calculator for the Concentration of a Substance

Calculates the concentration of the mass of a substance or pollutant in a medium such as air. Such a pollutant can be particulates, which usually are measured in μg/m³, i.e. micrograms per cubic meter. Here the amount of the substance in another volume can be extrapolated or the concentration can be calculated from the amount in a room. The calculation is the same as for density, but the units of mass are smaller here. Of course, this calculation is not limited to pollutants, but can also be done for desired substances.

Example: with a particulate pollution of 30 μg/m³ there are 18 milligrams of particulates in a room of 600 cubic meters. Depending on the type of particulate pollution, this value can be considered tolerable or already too high; there are different limit values ​​for different particle sizes.

In more general terms, the term concentration means the proportion of something specific in the whole. If proportion and whole have the same unit, for example kilograms for mass or cubic meters for volume, then such a concentration can simply be expressed as a percentage. The calculator above, however, refers to the special but frequently used case of mass of a proportion per volume of a whole. Such a concentration is referred to, particularly in chemistry, as mass concentration or partial density. The whole is often a substance that is present in excess; in addition to air, this can also be water, for example. In many cases, the proportion is something that is only present in small quantities, but which nevertheless plays an important role. Of course, such a concentration does not always have to be in the milligram range; for example, the salt content of sea water is 35 grams per liter, or 35 kilograms per cubic meter.