For food products produced by the grain industries, moisture is a crucial issue throughout the manufacturing process. Too little or too much moisture at different stages of production can affect the quality of the final product and the optimisation of production costs. By using microwave technology, it is possible to monitor moisture online, allowing trend analysis and early intervention when necessary. The Berthold moisture systems can measure grain moisture when harvested, throughout processing, and before storage and sale. This significantly reduces production costs and improves product quality. For example, as a rule the moisture content of couscous must not exceed 13.5%.

Early recognition of fluctuations

The MicroPolar system provides real-time, continuous measurement of moisture or dry matter content in a wide range of products. The measurement is performed directly on the main stream. This microwave measurement is non-intrusive; no sensor comes into contact with the product to be measured, which reduces maintenance. The measurement is not influenced by the colour, viscosity or inhomogeneity of the product. Moreover, the measurement is carried out on the entire product. The MicroPolar system is easy to install. The processing unit has a large display and a user-friendly interface. Calibration can also be performed on site.

Measuring principle and function

The installation possibilities are manifold, common installation situations are e.g. on pipes, belt conveyor, shafts / chutes. Possible applications are on all types of cereals, grains and powder products including maize, semolina and couscous, as well as soya, rice, coffee, starch, nuts, rice, etc.

The microwaves pass through the product to be measured, causing the free water molecules, which have excellent dielectric properties, to rotate. This rotation causes a slowing down (phase shift) and a decrease in amplitude (attenuation) of the microwaves, resulting in a very accurate measurement of the water content. Thanks to the multifrequency technique used by Berthold, measurements are highly reliable and stable and are not affected by reflectance or resonance. The integrated reference signal ensures excellent compensation for the influence of environmental parameters. As the device generates very low power microwaves (in the range of 0.1 mW), the measured product is not subject to any temperature increase or change. The radio licenses of the system have been approved by FCC, IC and ETSI.

These are the advantages of Berthold’s moisture measurement used for the food industry: 

  • Measures moisture across a representative product path
  • Energy reduction in drying processes
  • Increased yield through reduced amount of rejects
  • Free of wear and maintenance
  • Online process control for real-time process information
  • Highly representative due to transmission principle
  • Easy to install on existing pipelines, vessels, and conveyors