Importance

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Abstract

A method and apparatus for measuring the thickness corrected moisture ratio of a material, particularly organic material, comprising transmitting microwaves and measuring therewith the damping (A) and phase change (F1) of the microwaves upon their transmission through the material. According to the invention (W.sub.w /Y) is calculated from the expression A=(W.sub.w /Y).multidot. .multidot.k.sub.1 +k.sub.3 .multidot.t, where t is the thickness of the material (10) and where k.sub.1 and k.sub.3 are constants and the term W.sub.w /Y is the weight of the water in the material per unit area. In addition, the term (W.sub.d /Y) is determined from the expression F1=(W.sub.w /Y).multidot.k.sub.4 +(W.sub.d /Y).multidot.k.sub.5 +k.sub.6 .multidot.t in which expression the aforedetermined term W.sub.w /Y is used. The term W.sub.d /Y is the weight of the material in a dry state per unit area and k.sub.4, k.sub.5, k.sub.6 are constants. The moisture ratio is obtained in a known manner through the quotient (W.sub.w /Y)/(W.sub.d /Y). In this way the effect of the material thickness on damping (A) and phase change (F1) is included in the determination of the moisture ratio of the material.

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First Claim