UV spectral measurements at the RMI (Uccle, Belgium) date back as far as 1989. Over the long time period 1989-2004 the frequency of observations and calibration checks has changed. A description of the software tools developed to manage the different calibration levels and the reanalysis of the whole set will be explained. The methodology takes the temperature of the instrument into account, and in this way the estimated error on the measurements is less than 5%. This reprocessed dataseries of spectral data is used to construct a data set of UV indices. The resulting time series will be examined for the temporal evolution, in relation with the concurrent ozone observations and other ancillary data at the same site.