Precise shipboard determination of dissolved oxygen (Winkler procedure) for productivity studies with a commercial system1

Abstract
An automatic system of dissolved oxygen titration based on a potentiometric endpoint detector is described. The equipment is a simple commercial apparatus that can be used by a relatively unskilled operator. The C.V. of the oxygen measurement is 0.1% The titration is quick (3–5 min) and suitable for field studies of phytoplankton production and related subjects.