1 min readSpectrum TestingRobert E. LewisWeb Community ManagerFeb 26, 2015 Image Article LETF spectrum testing with a spectroradiometer of an red-green-blue LED light source. NASA LETF spectrum testing with a spectroradiometer of an red-green-blue LED light source. Share Details Last Updated Aug 29, 2023 EditorRobert E. Lewis Related TermsHuman Health and Performance