The ORNL ion-atom merged-beams apparatus has measured absolute electron capture cross sections for the multicharged ions O⁵⁺ on H(D) from 0.9 eV/u to 766 eV/u (C. C. Havener, M. S. Huq, H. F. Krause, P. A. Schulz, and R. A. Phaneuf, Physical Review A, 391725 (1989)). This publication contains details of the merged-beams method. Due to an unexpected large angular scattering for this sytem, it was predicted (Andersson et al. J. Phys. B, 24 2073 (1991)) that significant signal could be lost around 1 eV/u resulting in the observed structure in the total cross section, structure not seen in the calculation. Also, the observed signal was suspected to be high due to the presence of H rydbergs in the beam. New measurements were performed with improved angular collection and which were also corrected for H Rydbergs. ( C. C. Havener, F. W. Meyer, and R. A. Phaneuf, ICPEAC XVII, Brisbane 1991, invited paper, in "Physics of Electronic and Atomic Collisions", IOP Pub., 1992, page 381). The new measurements were performed with D (to maximize angular collection) in the energy range from 0.14 to 104 eV/u. Good agreement with theory is observed including a sharp increase at low energies due to trajectory effects.