2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/3077Radio sources are often polarized. Accurate measurement of simply the flux density of a radio source requires a basic understanding of polarization and its measurement techniques. We provide an introductory, heuristic discussion of these matters with an emphasis on practical application and avoiding pitfalls.21 pages, 9 figures. Presented at the Arecibo single-dish summer school, June 2001. Will appear in the ASP Conference SeriesAstrophysicstext