Feuchtegehalts

Feuchtegehalt, often translated as moisture content, is a measure of the amount of water contained in a material. It is commonly expressed as a percentage of the dry mass of the sample, defined by the relation w = (m_w / m_d) × 100%, where m_w is the mass of water and m_d is the oven-dried mass of the sample. This mass-based definition is widely used across materials such as wood, textiles, foods and soils. In soils, moisture content can also be described gravimetrically (water mass per dry soil mass) or volumetrically (water volume per total volume), depending on the context and measurement method.

Measurement methods range from traditional oven-drying, where the sample is dried at about 105°C to constant mass, to non-destructive techniques such as dielectric moisture meters, infrared or near-infrared sensors, and, in soil science, gravimetric sampling with laboratory or field sensors. The choice of method depends on accuracy requirements, material type, and whether a destructive or non-destructive approach is acceptable.

The Feuchtegehalt is influenced by environmental conditions, particularly relative humidity and temperature, and tends to move toward an equilibrium moisture content (EMC) under steady conditions. EMC is material- and environment-specific and governs dimensional changes, mechanical properties, and susceptibility to decay in many materials.

Applications and significance vary by field: in wood and textiles, moisture content affects strength, elasticity, shrinkage, and processing; in construction, it influences adhesive performance and durability; in agriculture, soil moisture content determines plant available water and irrigation planning. Typical values differ widely by material and context, underscoring the importance of appropriate measurement and control.