The direct result of a spectrometric measurement is a pulse height distribution. In the energy region up to 300 keV three corrections in particular need to be applied to get the photon spectrum: corrections for K-escape, Compton scattering and inefficient photon absorption. A simple 'stripping' procedures is described which may be implemented on a desk type computer. All data necessary are either available in the literature or may be derived from the measurement of very heavily filtered X-ray spectra. The accuracy of the procedure is better than ± 5% of the peak value. Results are compared with a more detailed stripping procedure, based on Monte Carlo calculated data.