A auto-calibrated microhole cathode array dissolved oxygen and ionic conductivity sensor

Abstract

A novel miniature auto-calibrated dissolved oxygen and ionic conductivity sensor has been developed. This sensor consists of two gold working electrodes, a Ag/AgCl reference electrode, a gold counter-electrode, and a Pt thermal resistant. It operates in a three-electrode potentiostatic mode. The two working electrodes have a multiple-cathode array separately. One is used for the measurement of oxygen and the other is used for calibration. The two working electrodes can also be used to measure the conductance of a solution by switching the sensor to the conductance measurement circuit. Evaluation of the sensor characteristics was undertaken and the results are promising. Calibration of the sensor was performed over the oxygen concentration range of 3-16 p.p.m. in a 0.1 N-1 N KCl solution in the 12-25 degrees C temperature range and at 760 torr pressure. A linear relationship is observed.<>