We describe here two experiments presently running al PSI using the NA2 polarized neutron beam. They are devoted to the measurement of 2- or 3-spins observables in np elastic scattering for kinetic energies from 230 to 590 MeV with a tcnlcr of mass angular range from 60 to 180 degrees. The goal is to determine the five NN scattering amplitudes for isospin 0 in a model independent way. Preliminary results for Kosko and Kosso spin-transfers are presented.