Excellent properties of a dispersive double-crystal monochromator for the use in powder diffractometry, namely for strain/stress measurements are presented. For this purpose a strongly dispersive double crystal setting consisting of a mosaic Ge(331) (mosaicity eta of about 16') and bent perfect Si(111) crystal set for diffraction at the neutron wavelength of lambda=0.1835 nm, was used. The optimized arrangement provides good luminosity and a sufficiently high resolution (FWHM of the instrumental Deltad/d - profile can be about 3x10(-3) in the vicinity of the lattice spacing d =0.13 nm (2theta(s) approximate to +/-90degrees) for both parallel and antiparallel scattering geometry, simultaneously.