Investigation on Surface Resistance Characteristics and Equivalent Salt Density of Composite Insulating Flat Plate Polluted by CaSO₄ and NaNO₃

This study explores the surface resistance characteristics and equivalent salt density of composite insulating flat plates contaminated with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{CaSO_{4}}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{NaNO_{3}}$</tex>. In the experiment, insulating flat plates coated with RTV coatings are used. After being treated with diatomaceous earth, their surfaces are contaminated. By measuring the surface resistance under different soluble contaminant densities (SCD), the results show that as the SCD increases, the surface resistance value shows a downward trend, and the surface resistance value of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{NaNO_{3}}$</tex> is lower than that of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{CaSO_{4}}$</tex>. Further research on the resistance characteristics of mixed contamination reveals that when the mass fraction of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{CaSO_{4}}$</tex> increases, the surface resistance value of the composite flat plate significantly increases. The calculation of equivalent salt density indicates that under the same conditions for <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{CaSO_{4}}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{NaNO_{3}}$</tex>, the equivalent salt density of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{CaSO_{4}}$</tex> is lower than that of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{NaNO_{3}}$</tex>. The research results provide an experimental basis for the performance evaluation of insulating materials under contamination conditions.