2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197612TRIUMF experiment 497 has measured the parity violating longitudinal analyzing power, A_z, in pp elastic scattering at 221.3 MeV incident proton energy. This paper includes details of the corrections, some of magnitude comparable to A_z itself, required to arrive at the final result. The largest correction was for the effects of first moments of transverse polarization. The addition of the result, A_z=(0.84 \pm 0.29 (stat.) \pm 0.17 (syst.)) \times 10^{-7}, to the pp parity violation experimental data base greatly improves the experimental constraints on the weak meson-nucleon coupling constants h^{pp}_ρand h^{pp}_ω, and has implications for the interpretation of electron parity violation experiments.17 pages RevTeX, 14 PostScript figures. Revised version with additions suggested by Phys. Rev. CNuclear ExperimentHigh Energy Physics - Phenomenologytext