MEASUREMENT OF THE AREA DENSITY OF A MATERIAL WITH A UNIFORM STRUCTURE USING THE ULTRASONIC METHOD

Abstract

As a result of the production, processing of paper raw materials and obtaining at the output of the finished product, which is a homogeneous structure, the manufacturer strives to obtain a high quality of the finished product. To achieve this goal, the task of measuring and controlling the area density of homogeneous paper material during its production, which directly affects its quality, is relevant. Today, paper industry enterprises use the contact destructive method of determining the area density of the material, which does not provide the opportunity to implement constant monitoring of the parameter. In order to solve this problem, it is necessary to develop new computerized systems and methods of measuring the area density of the material using non-contact ultrasonic transducers, since only they provide an opportunity to monitor the parameter in real time at low financial costs for their installation and operation in comparison with analogues.

To develop a non-contact method of measuring the area density of a homogeneous material, the following tasks must be solved: to investigate the theory of propagation and attenuation of ultrasonic waves in a controlled material with a homogeneous structure; state the main amplitude ratios of ultrasonic waves that interact with the material; to develop an algorithm of measurement and calculation procedures to determine the area density parameter of the material, which will be applied in the computerized system.

To control the material, it is necessary to take into account the features of the material composition and its influence on the informative parameters of the probing ultrasonic signal itself during the measurement. With the non-contact ultrasonic method, the material is irradiated with waves, and the value of its area density is determined by the ratio of the amplitudes of the ultrasonic wave that passed through the material with a uniform structure and the wave that falls on it. A reference channel is used to adjust the computerized information and measurement system to the environmental parameters before starting the measurement of the area density of the material.