Optical D.O. measurement based on dye luminescence is strongly promoted in these days. The manufacturers of such instruments claim far superior performance compared to conventional electrochemical sensors. In theory, the functional principle of the optical D.O. measurement confirms this superiority. However, practical realisation and application does set certain limits and, as usual, further technical development is needed to bring theory and practice to accordance.
WTW's FDO 700 IQ D.O. sensor belongs to a new generation of these sensors that eliminate the shortcomings of the former ones. Its most remarkable features are: High accuracy right from the start, maximum stability over a long timespan and minimum maintenance effort.