Scientific Journal of KubSAU

Nowadays the method of finite elements (MFE) is a standard method of acoustic analysis. It consists in finding the solution of the function on the maximum allowable quantity of piecewise continuous functions that are determined in allowed number of subdomains. The number of sub-domains has a finite value but an unknown continuous value is approximated by the polynomial on each element that acquires specific values in the nodes. Polynomials can be various but all of them produce continuity of total value along its limits. Herewith because of technical features of the calculation process minimization of numbers of polynomials is required according to the criterion of acceptable precision. In the chosen COMSOL Multiphysics program model the range of frequencies under analysis is the result of the sum of 10 segments (sub-ranges). Such a sub-range is a minimal discrete value in certain conditions of calculation. Thus, the calculated value on this subrange can be considered as the result of calculation by means of using the band-pass filter with 35 Hz bandwidth. Because of this, we can draw a conclusion about changing the state change of the noise exposure on the combine operator with respect to the previous measurement according to the regulatory methodology. Hereinafter if the stated change of the noise exposure is found, measurements that are more precise are taken. On the basis of these measurements the head of the company receives recommendations either on verification of stated acoustic characteristics of devices and mechanisms of a harvester or on verification of acoustic ways of transmission of structural noise (noise created by devices that penetrates into the booth through the combine body), or on verification of noise isolation of the booth

In this article, we have examined the methodology of acoustic measuring with the purpose to create safety conditions for the activity of agricultural machines operators, in foremost harvesters and tractors. We should underline that such studies are based on the state standards that are aimed at improving the level of comfort of the activity of the operators of tractors and harvesters and maintaining their working capacities. Therefore, there is a need for a thorough analysis of the current regulatory legislation (standards that are applied) in combination with analysis of mathematical support of measuring devices (sound level meter). Besides, there is a need for creating strict sequence of actions of the sound level meter operator (algorithm) in combination with the method of conveying information that is adapted to the experiment. At the enterprises, organizations and establishments control of the noise level at working places is checked no less than once a year. The State Standard 12.4.095-80 provides the basis for measuring, position of the control point in the booth, the frame and characteristics of measuring, mode of activity of engines and parts of harvesters, the amount of measurement samples (3 precise measurements), estimation of measurements and their correction, equipment, methods of measuring the results, temporary characteristics of measuring by the sound level meter in “slow” mode and frequency correction

Here we present a brief survey of the occurrence of noise in agricultural production while using agricultural machinery and machines with possibility of application of the newest technologies including informational ones. It is well known, that noise is a constant component of all agricultural enterprises and it often indicates the operational condition of equipment and technical culture of enterprises. This is true about both stationary production, such as elevators, grinding plants, feed mills, corn processing plants, and tractors and harvesters. It is natural that above-mentioned mechanisms produce purposeful transformation of the movement. At the same time, any mechanism consists of separate parts that are flexibly joined with each other. In addition, it is due to this fact that the noise occurs. Thus, we should note that due to their design features and complexity of technology itself harvesters a priori are machines that create and produce noise. Noise reduction in machines and equipment is accompanied by increase of labor productivity. Thus, noise protection is an important issue. To reduce the noise a set of measures is applied but not all of them are efficient for selfpropelled machines, including harvesters. Besides, noise is one of the most important indicators of equipment quality, and in some cases, it can be the indicator of the technical level of a machine because it objectively displays inaccuracies in the manufacture of almost all parts. Therefore, noise control is an important problem that has social and economic value

Here we present a brief survey of noise effects on human’s organism in production conditions, including noise effects on operators of machines and technical devices. It is well known, that any biological organism exists in balance with its environment. However, noise effects being stress factors knock the operator of machines and technical devices out of the working rhythm and cause different kinds of health disorders such as blood pressure increase, fatigue, disorders of the central nervous system and gastrointestinal tract and the like. All this may lead to accident situations, reduction of labor productivity and quality of work. Frequently health disorders start with hearing impairment which leads to disorientation in the threedimension space and malfunction. It is because the hearing apparatus as biological system provides the organism with sensory information and ensures selfpreservation. In the noise conditions, these characteristics are conflict: on one hand, the hearing organ should possess high enabling capability to receive positive signals, and on the other hand, in order to adapt to the sound hearing and sensitivity will decrease. The duration of noise exposure and the number of years spent under influence of the noise are also of great importance. Thus, it is obvious that control of the noise and prevention of harmful effects of the noise on machine operators are important components of production process in the agrarian sector