Measuring moisture in asphalt mixes - Berthold Technologies GmbH & Co.KG

Online measurement to improve quality

Microwave measurement is nonintrusive; there is no sensor that comes into contact with the product to be measured, which limits maintenance and avoids special cleaning. The measurement is not influenced by the colour or inhomogeneity of the measured product. Furthermore, the measurement is carried out on the entire product. In addition, the multi-frequency technique enhance the stability and representativeness of the result. The Micro-Polar system is easy to install. The processing unit has a large display and a user-friendly interface. Automatic calibration can be carried out on site.

Microwave moisture measuring principle

The microwaves pass through the product to be measured, causing rotation of the free water molecules. They have excellent dielectric properties. This rotation causes the microwaves to slow down (phase shift) and decrease in amplitude (attenuation), resulting in a very accurate measurement of the water content. Thanks to the multi-frequency technique used by Berthold, the measurements are highly reliable and stable and are not affected by reflectance or resonance. The integrated reference line provides excellent compensation of the influence of environmental parameters. As the device generates very low power microwaves (about 0.1 mW), the measured product does not undergo any temperature rise or changes. The radio licenses for the system have been approved by the FCC, IC and ETSI.