Moisture content estimation in paper pulp using fringing field impedance spectroscopy

Currently used methods for estimation of moisture content in paper pulp are restricted to levels of moisture concentration below 90%. Some of the existing methods require less practical double-sided contact measurements. A few other methods make restrictive assumptions, such as the constituents of the pulp that determine its conductance. This paper presents a technique that uses fringing field interdigital sensors to measure moisture concentration in paper pulp at levels as high as 96%. The method proposed in this paper uses single-sided measurements, offers high sensitivity, and does not require special operating conditions. The accuracy of the proposed method is also demonstrated. The repeatability and reproducibility of the sensor measurements are also shown.