INFORMATION-ENTROPY METHOD FOR DETERMINING THE HOMOGENEITY OF ELECTRIC HEATERS USED IN AGRICULTURE
Low-temperature surface-distributed electric heating is currently considered to be the most effective type of electrical heating. It provides the concentration of thermal energy in a given volume, the uniformity of temperature distribution and the possibility of its control andregulation, and it is increasingly used in agricultural production. According to the data of the Ministry of Agriculture and Foodstuffs of the Russian Federation on the 1 st of October, 2010 there were 154.6 million different installations and local heating devices in exploitation in Russia's livestock farms. Proportion of costs for heating grain and bulk solids in the processing industry is invariably great. In this regard an important reserve for improving the efficiency of production is the development and introduction of progressive systems of an electrical heating that provide the required performance property for the rational use of energy and material resources. The system, which main function is the conversion of electrical energy into thermal energy and, at the same time, providing a set-point temperature (300…400 K) on the surface, is called composite heaters. At present, the overwhelming majority of electric heaters contains a resistive composite layer in which electrodes are located between the insulating layers. The electrical conductivity is estimated by the specific resistance, the specific resistance of the composite material is significantly affected by its homogeneity. It makes the proof of the homogeneity of this material a topical issue. In the article an information- entropic method for determining the homogeneity of the composite material is developed, it is based on the probability theory and the concept of entropy. A comparative analysis of the developed method with existing techniques for determining the homogeneity of the distribution of technical carbon in the butyl rubber matrix is given in the article.