2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/9479Photon yields in damp air excited by an electron using a Sr90 $β$ source are compared withthose in dry air. Water vapors considerably reduce the yields, however, a further study is needed to evaluate the effects on the energy estimation of ultrahigh-energy cosmic rays. The relation of fluorescence efficiency to the life time of de-excitation by radiation is discussed.4 pages, 3 figures. Proceedings of 29th International Cosmic Ray Conference (ICRC) 2005, Pune, IndiaAstrophysicstext