In this paper we attempt to quantitatively describe the process of diffusion of Nickel atoms to the copper substrate, taking into account the accelerated diffusion along the grain boundaries. A model experiment allows us to get guidance on the selection of the optimum thickness of the Nickel coating to ensure stable operation of wire with desired characteristics

Keywords: Nickel coating, the optimum thickness, copper wire, enhanced diffusion, diffusion coefficient, diffusion distribution of atoms, the grain boundary, modeling, task Fisher

A method of prognosis of gas sensitivity's coefficient of conductometric gas sensors with sensitive layer which is based on a semiconductor with deep energy levels in the fobidden zone was developed. As a result it was found out that deep energy levels can cause a significant increasing of gas sensitivity's coefficient as well as influence on the chemosorptive properties of sensitive layer.

Keywords: Сonductometric gas sensor, gas sensitivity, sensitive layer, semiconductor, deep-lying levels.