The spectroscopic signature of roAp stars

To reliably determine the spectroscopic signature of rapidly oscillating chemically peculiar (roAp) stars it is also necessary to investigate a sample of non pulsating chemically peculiar (noAp) as well as presumably normal stars. We describe in this study the sample of spectroscopically investigated stars and comment on the techniques used for the analysis. In particular we discuss ionization disequilibria of rare earths in roAp stars that distinguish them from noAp stars. In the light of the recently discovered pulsation of beta CrB we see arguments that all magnetic CP2 stars up to a transition temperature of about 8100 K may be pulsating.