The authors have obtained high-resolution spectrograms of H-rich central stars of planetary nebulae (CSPN) with the 3.6 m telescope and Cassegrain echelle spectrograph of the European Southern Observatory. They have determined the basic atmospheric parameters (Teff, log g, photospheric He abundance) for 22 of these CSPN, by fitting the observed stellar H and He absorption line profiles with theoretical profiles, obtained from improved non-LTE model atmosphere and line formation calculations. Restricting the attention to those CSPN that are post-AGB objects, the distances have been calculated that result from the assumption that the theoretical mass-luminosity relation for post-AGB stars is valid for CSPN.