Abstract: A dual parameter spectrometer is developed with which the anode and cathode signals of the gridded ionization chamber are recorded simultaneously, a computer program is designed to collect, display and store the two dimensional spectra. Alpha sources are measured with the spectrometer and the angle distribution of alpha particles are calculated. It is discussed how to correct the effects of back scattering and self absorption in the measurement of activity with the angle distribution and it is pointed out that the resolution of the energy spectra can be improved by using the angle distribution as well.