[en] We report an absolute measurement of the tensor analyzing powers T20 and T22 in elastic electron-deuteron scattering at a momentum transfer of 1.6 fm^-1. The novel approach of this measurement is the use of a tensor polarized 2H target internal to an electron storage ring, with in situ measurement of the polarization of the target gas. Scattered electrons and recoil deuterons were detected in coincidence with two large acceptance nonmagnetic detectors. The techniques demonstrated have broad applicability to further measurements of spin-dependent electron scattering