Pressure balanced type membrane covered polarographic oxygen detectors for use in high temperature-high pressure water, 2

Performance tests of a pressure balanced type membrane covered polarographic oxygen detector were carried out in water at 2850C (BWR operating conditions) to determine the effects of environmental factors. Dependencies of detector current on pressure and sample water flow velocity were ascertained and response time of the detector was determined. Effects of H2 present in the water were also examined. The following conclusions were obtained: (1) The detector current increased in proportion to the 0.67th power of the flow velocity, but was independent of the pressure. (2) Response time was about 7s. (3) Hydrogen caused a decrease in the current at cathode potentials more positive than -0.75V against the Ag/AgCl electrode. However, at more negative potentials, the current was independent of H2 concentration and in proportion to O2 concentration. Oxygen concentrations in water containing H2 at 2850C could be determined by the detector under the measurement conditions of constant flow velocity and cathode potentials more negative than -0.75V. (author)