Patent ID: 7615139
Filing Date: 2009-11-10
Classification: G01N

Abstract:
1. An electrochemical sensor, comprising: a housing body with an opening: a diffusion membrane covering said opening; an electrolyte in said housing body; a measuring electrode in said housing body adjacent to said opening and in contact with said electrolyte; a reference electrode consisting of a carbon containing material, said reference electrode being in said housing body in contact with said electrolyte; a protective electrode in said housing body in contact with said electrolyte and arranged adjacent to said reference electrode at least partially surrounding said reference electrode for shielding said reference electrode against substances that would lead to a change in a reference potential when reaching said reference electrode; an auxiliary electrode; a mediator material in said housing body for essentially determining an electrical potential of said reference electrode; and a sensor circuit connected to each of said measuring electrode, said reference electrode, said protective electrode and said auxiliary electrode for setting said measuring electrode at one of settable potentials and for setting the protective electrode at one of settable potentials and for determining a voltage difference between said measuring electrode and said reference electrode, for determining a voltage difference between said protective electrode and said reference electrode, and for determining a current flow through said measuring electrode and through said protective electrode, and including a microcontroller for setting said settable potentials and for receiving signals representing each said determined voltage difference and said current flow.