Radio-continuum measurements of planetary nebulae at 15.5 GHz

We have accurately observed 17 planetary nebulae at the reasonably high microwave frequency of 15.5 GHz. Estimates of interstellar extinction derived from measurements of flux density compare favorably with those evaluated from a dust model of the Galaxy and with those derived from intensity ratio of Paschen and Balmer lines of hydrogen. The ionic abundance ratio 0+ + /H + is obtained by a new technique and is consistent with values found by other methods. Subject headings: abundances, nebular - interstellar reddening - planetary nebulae - radio radiation