Measurement of the moisture content of fiber in a layer of variable thickness

Conclusions

The experiment showed that the joint use of two fundamentally different methods (in this case radioactive and capacitive) allows contactless measurement of the moisture content of wool and staple fiber in a layer of variable thickness; the root-mean-square error of measuring the moisture content of the fiber upon a change of the bulk thickness of the layer from 0.1 to 0.6 g/cm². was ±1%. The accuracy can be greatly improved by measuring the capacitance of the transducer at higher frequencies, 1.5–10 MHz. By using a comparatively simple computer the method permits automating the operation of the drier and obtaining information not only on the moisture content but also on the dry weight of the specimen. We can assume that (9) is applicable both for determining the moisture content of capillary-porous colloid materials in a layer of variable thickness (cloth, paper, cardboard, leather, food products) and for other cases where capacitive methods of measuring moisture content are used, but a change of the bulk thickness of the layer being monitored introduces substantial errors.