The Uvector MPI ultraviolet intensity sensor for Berson's medium-pressure ranges, supplied on a core-exchange basis: the price shown applies against return of the old sensor. Order the outright-purchase listing, item 1047-1205, if no core is being returned. The sensor reports the UV-C actually reaching the water, which is the measured variable a validated disinfection duty is controlled and alarmed on. Berson UV-techniek of Nuenen, the Netherlands, has built ultraviolet disinfection plant since 1972 and is part of the Halma UV group alongside Hanovia and Aquionics.