Precise and reliable moisture measurement reduces costs and environmental impact

Engineered wood, biofuels, seeds, food and fodder – these and other raw materials and substances have one thing in common: Moisture can damage them over a long period or adversely affect their quality and prevent them from being used or further processed. For all companies that process these and similar raw materials, moisture measurement is therefore a fundamental work step. Not only does it have a preventive function, but it is also used to monitor drying processes.

In the industrial production process, manual sample measurement is frequently used to monitor belt, drum or counterflow dryers.

The result is that drying times are often unnecessarily prolonged or shortened over the times that are actually required. This lack of efficiency is both a cost factor and an environmental factor because drying processes entail high energy consumption. With regular, reliable moisture measurement during drying, drying times can be reduced to just the amount that is necessary.

Various physical measuring principles are used to determine moisture in materials. In industrial moisture measurement, systems have proven successful that use microwaves to quantify water molecules. They penetrate right through the product and can thus measure both the moisture on the surface and in the interior. A single measurement takes only a few milliseconds and is highly precise.

The 2-parameter microwave resonance method (2PMR) developed in 2001 in cooperation between Döscher and the Chair of Microwave Engineering at the Christian-Albrechts-Universität zu Kiel, uses a static electromagnetic field and measures changes in the interaction with water molecules. By detecting the energy loss of the field as a reaction to the alignment of the H₂O molecules and measuring the propagation speed of the microwaves, it is possible to determine the number of water molecules and therefore the water content precisely.

"Our customers achieve optimum results in the coordination of drying times by using dryers with integrated moisture measurement using 2-parameter microwave resonance methods", Jörn Döscher, CEO of Döscher Microwave Systems GmbH, explains. "Many suppliers and users of dryers dispense with integrating continuous measurement of the water content in the production process for cost reasons", Döscher says. "However, measurement that is permanent, accurate and stable over a long period can reduce production costs and thus justify the necessary investment."

Döscher Microwave Systems GmbH was founded in 2014 by merging Döscher & Döscher GmbH with AMS Advanced Microwave Systems GmbH. Based in Rellingen, Schleswig-Holstein, directly on the border with Hamburg, Döscher develops and manufactures measuring systems for moisture measurement, and grammage measurement and density measurement, for use in manufacturing industries and as laboratory apparatus. The VenScan and MoistureScan measuring systems permit moisture control directly in the product flow for various production processes and therefore support optimum process control.