What type of material is measured by moisture content?

Moisture content is a critical factor in assessing the properties of soils. In geotechnical engineering and environmental studies, the moisture content of soil significantly affects its behavior, strength, and stability. It is a measure of the amount of water present in the soil relative to the weight of the dry soil. This measurement is essential for tasks such as determining the suitability of soil for construction, agricultural activities, and understanding drainage issues.

In contrast, while air contains moisture (water vapor), the measurement of moisture content is not applied to air in the same way it is for soils. Water itself is also not measured by moisture content, as that term specifically refers to the water-filling ratio in solid materials such as soil. Concrete can absorb moisture, and its performance can be influenced by water content, but the term "moisture content" is less commonly associated with concrete compared to soils. Therefore, soils are the primary material for which moisture content is a standard and critical measurement.