concentration measurement

Microwaves are highly sensitive to water molecules. When penetrating the measured material, microwaves transfer energy to free water molecules, causing them to rotate. As a result, the velocity of the microwave is slowed down (phase shift) and their intensity is weakened (attenuation). Phase shift and attenuation are a direct measure for the water content,which indicates the concentration or amount of dry substance. Both effects are measured by our sensors, allowing for a very stable measurement. 
These measuring effects are achieved with very small microwave transmission power – typically 0.1 mW. Consequently, the measured material is neither warmed nor modified. Berthold measures via transmssion, penetrating through a cross-section of the material. This  ensures the measurement is representative of bulk moisture, instead of a surface measurement, and therefore the measurement is highly accurate and representative. Factors such as colour, viscosity, nonhomogeneous composition, and dust have no or only a negligible effect on the measurement performance.