Investigation of the Possibility to Provide the Capacitive Moisture Sensing, Invariant to the Composition of a Bulk Substance or Dispresive Medium
Oleksandr V. Zabolotnyi, Vitalii Zabolotnyi, Vitalii P. Siroklyn · 2024
Different physicochemical composition of the dehydrated substances makes capacitive moisture meters sensitive to the ‘type uncertainty’. Traditional ways of the ‘type uncertainty’ compensation are effective when we know the composition of the substance and stop working when the composition is unpredictable. The solution is to use dedicated testing influences on the moist substance. Firstly, we have to measure the dielectric permittivity of the initial sample. Then, we have to perform two injections of moisture (testing influences). It helps to receive three transfer functions for the moisture meter, invariant to the type of moist substance but strongly nonlinear. The method of linearization, together with the substitution of direct water additives with another procedure equivalent to the real physical model of a humid substance, was investigated. It can be concluded that the method of linearization provided close to the linear equivalent of three transfer functions, which were strongly nonlinear. The procedure of simulating the direct water additives into a humid substance with metallic flat plates of different widths provided a partial solution, more suitable for water in oil (water-fuel) emulsions than humid bulks.