Аннотация:The structure of the superconducting order parameter of weakly underdoped BaFe1.92Ni0.08As2 pnictides with the critical temperature Tc ≈ 18.2 K has been determined. Two microscopic superconducting order parameters - the small superconducting gap Δ_S(0) and, supposedly, the edges of the large gap Δ_L(0) with anisotropy in the ab plane — have been determined at T << Tc, together with their temperature dependences, using incoherent multiple Andreev reflection (MAR) spectroscopy. It has been shown that the determined temperature dependence of the lower critical field H_c1(T) can be described in the two-band approximation both within the so-called alpha model (using experimental superconducting gap values at T=0) and using gap temperature dependences Δ(T) obtained by (MAR) spectroscopy under the assumption of a fairly strong anisotropy of the small superconducting gap, where the experimental Δ_S(0) value is taken as the outer edge of its angular distribution.