A velocity magnitude transducer for use with saline containing dissolved oxygen

The theoretical response of an oxygen-reducing copper cathode to saline velocity is described for a range of electrode shapes and sizes and an experimental study of various velocity magnitude transducers based on the effect is presented. A preferred form of transducer is suggested which is small, requires one-sided access to low-volume solutions and has a symmetrical square-root response to velocity magnitude covering typically the range from 800 to 1 mm s^-1. The time dependence of the response and other factors limiting the performance of the transducer are discussed.