Electron Temperatures and Densities of Compact Planetary Nebulae

We present preliminary results from an optical spectroscopic survey of compact planetary nebulae (PNe) in the Galactic disk. This is an ongoing optical+infrared spectral survey of 150 compact PNe to build a complete database of Galactic PN chemical abundances. We obtained optical spectra of 27 PNe with the Southern Astrophysical Research (SOAR) Telescope in 2012 and 2013. Here we present physical diagnostics such as electron temperature and density for each PN derived from the reddening-corrected line intensities, and compare these to dust thermal temperature and dust type derived from Spitzer spectra. We will use these diagnostics to derive the elemental abundance of He, N, O Ne, S and Ar from combined optical and IR spectra in subsequent analyses.