The renewed concern about the ozone layer initiated a project of monitoring the total ozone in 1987. A Brewer ozone spectrophotometer at the Swedish Meteorological and Hydrological Institute (SMHI) in Norrkoeping and previously used for solar ultraviolet radiation measurements was repaired and recalibrated. It is now in regular operation since February 1988. This report summarizes the measurements and efforts during 1990. Changes in the observation schedules have been undertaken. The software was modified to improve measurements at low solar elevations, which are especially important during the winter season at high latitudes. Daily values of the valuable Dobson measurements from Uppsala during the period 1951 to 1966 have been processed and these are compared with more recent measurements in Norrkoeping. The effects of using different ways to compute average monthly values of an incomplete set of data are briefly discussed. The longterm variation of total ozone at these stations is presented. A new station has been established at Vindeln, in the northern part of Sweden, using the old Uppsala instrument, Dobson 30. Regular observations starts early 1991. 14 refs., 29 figs.