MICROWAVE METHOD OF MEASURING MOISTURE OBJECTS OF THE ARBITRARY FORM
Urgency of the research. Modern production technologies are largely related to moisture content. Excess or lack of moisture in the material affects its properties and also on qualitative indicators. Fast and accurate moisture content in a given material is very important and urgent task. Actual scientific researches and issues analysis. The microwave methods widely used to measure the moisture of materials. Free water molecules to spin electromagnetic field, resulting in a slowed speed of radio waves and their intensity decreases. These effects are used to create devices and systems that measure humidity using microwave signals. The work of most of them is based on determining the value of the signal attenuation or changes in the dielectric constant wet substance. The most widespread microwave methods are optical, resonance, waveguide, probe methods. Uninvestigated parts of general matters defining. The advantages of microwave measurement methods and control moisture include relatively high accuracy, non-destructive of the sample during the measurement, low power measuring systems and more. Almost all of these methods require knowledge of the geometric dimensions of the object that is not always possible. Also these methods require a certain location and orientation of the antenna, according to their pattern. The research objective. The development of microwave moisture measurement methods of building materials and engineering constructions for further use in non-destructive monitoring of arbitrary shape objects. The statement of basic materials. Waveguide-coaxial transition is one of the important components of microwave technology. It is widely used for mutual connections of waveguide and coaxial transmission lines when forming SHF channels. If microwave signal with a frequency slightly less than the maximum reaches the waveguide-coaxial transition and then frequency gradually increases, the power entering to the coaxial line will increase, because we approach the frequencies which are actually designed this waveguide-coaxial transition. On the other side, some substances have the rise of microwave signal attenuation with increasing frequency. Thus these two opposing factors lead to the availability on frequency depending of the degree of attenuation SHF waves clearly minimum. The authors found that the frequency of maximum weakening depends on the percentage of humidity of the sample. Conclusions. A new method of humidity control based on measuring the frequency at which the maximum microwave signal is attenuation in the waveguide-coaxial transition was offered. The results of experimental studies illustrate that frequency of maximum attenuation microwave signal depends on the humidity.