Two capacitive methods of measuring the linear density of one-dimensional fibrous products are considered. The sensitivity of the measurement results to variations in the geometric and physical parameters of the measuring device for the differential and resonance measurement methods is estimated. A weak, almost linear dependence of the measurement error on parameter variations in a wide variation range is established. The good suitability of both methods for measuring the linear density of one-dimensional products by the capacitive method and the high correlation between the measured value and the measurement results are substantiated.

Keywords: fibrous materials, one-dimensional products, linear density, capacitive measurement method, capacitive method, differential circuit, resonant measurement circuit, parameter variations

The article discusses a method for detecting defects in extended products. To find defects, scanning the product along its entire length is used. The result is a two-dimensional data stream that needs to be analyzed. The problem of detecting a defect is one of the tasks of detecting a “useful” signal against a background of “noise”. The most reliable method is to use a set of statistical criteria. To compare the mean values, the Student's test and two Wilcoxon–Mann–Whitney tests were used; to compare the scattering values, the Fisher test and the Ansari–Bradley test were used. The effectiveness of the algorithm was confirmed using a computer model simulating a two-dimensional homogeneous data stream.

Keywords: defects, extended products, computer model, simulation, statistical criterion