Mathematical model and design optimization of recessed dissolved oxygen cathode array

A mathematical model of recessed dissolved oxygen cathode array sensors is described. Three-dimensional cylindrical coordinate (R, Theta ,Z) finite element analysis with a trigonal ring element has been developed for analysis of the complex geometry of the recessed cathode array. Some principles for estimating sensitivity, response time, stability, diffusion crosstalk, and flow independence concurrently are provided. It is found that the microhole with a vertical wall is more effective in limiting the diffusion field than the wall slope with the same H/D ratio. In order to avoid the crosstalk of the diffusion fields of two microholes, their central distance must be larger than 1.9 D. A microhole cathode array three-electrode oxygen sensor has been developed using the results of the model.<>