Published online by Cambridge University Press: 19 July 2016
Good progress has been made since the last Symposium on the determination of planetary nebulae (PN) abundances. Notable features for modern abundance determinations include the availability of good collision strengths and transition probabilities (reviewed by C. Mendoza (1983) at the last meeting - IAU Symp.103), the use of the IUE & IRAS satellites to obtain UV & IR line fluxes, and the availability of modern sensitive detectors enabling measurements both of faint extra galactic nebulae and of very weak abundance-indicator lines in nearby bright nebulae. The impact of IUE on PN studies was described by Köppen & Aller (1987).