NUMERICAL-SIMULATION OF THE TIME-DEPENDENT CURRENT TO MEMBRANE-COVERED OXYGEN SENSORS .3. USE OF A MICROCATHODE IN PULSE AMPEROMETRY

In this paper we develop further a model for the operation of the Clar k electrode that we have described previously. Alteration of the bound ary conditions at the cathode surface enabled investigation of the use of such sensors in pulse amperometry. We first determine the optimal theoretical pulsing regime for particular electrode dimensions, before going on to investigate the response time of the sensor to a step cha nge in sample p(O2). These investigations show that pulse amperometry can, theoretically, overcome both the problems of flow sensitivity and slow response time associated with the use of sensors of this type in measuring oxygen in a biological environment.