Herasym M. Development of metrological assurance of electrophysical parameters measuring of qualimetry objects of nonelectric nature

The thesis is dedicated to the improvement of metrological assurance of electrical parameters measuring of non-electrical nature objects. The solution of problem is based on immittance parameters measurement of control object, supplied as a multi-element two-terminal network. Parameters of such two-terminal network characterize physical and chemical properties of control object. It is established that near-electrode phenomena (in particular, the capacity of the double layer) significantly affect on the measurement result. The electrical and mathematical models of primary contact transducers with considering of the near-electrode effects are shown. The influence of the near-electrode capacity on the measurement result of informative parameters is analyzed. Mathematical modeling of admittance components in a wide frequency range is conducted. The dependence of the admittance reactive component of the primary contact transducer with a low-frequency control object contains three ranges in which the component has its own character changes. According to the analysis of mathematical model we can select the frequency of the test signal or frequency range of electrophysical parameters research of non-electrical nature objects, using the primary contact transducers. The variants of construction of "impedance-voltage" transducers with four-electrode contact sensors are suggested. This approach allows to provide a result invariance of the measurement to the near-electrode capacity and to the change of signal parameters. It is found that the near-electrode capacity of primary contact transducer depends not only on the area of the electrode, but also on the inter-electrode distance.