Electrochemical fuel cell, process for maintaining an electrochemical fuel cell and breath alcohol measuring device

A breath alcohol measuring device comprising an electrochemical fuel cell, the electrochemical fuel cell comprising:

• a first electrode provided as a measuring electrode in a regular operating mode of the electrochemical fuel cell and as a measuring electrode or reference electrode in a maintenance mode of the electrochemical fuel cell;
• a second electrode provided as a counterelectrode in the regular operating mode of the electrochemical fuel cell and a measuring electrode or reference electrode in the maintenance mode of the electrochemical fuel cell;
• a third electrode provided as a counterelectrode in the maintenance mode of the electrochemical fuel cell;
• and
• a control module operatively connected to the first electrode, to the second electrode and to the third electrode and configured to control the first electrode, the second electrode and the third electrode to operate the electrochemical fuel cell alternatively in the regular operating mode or in the maintenance mode, to set, in a first phase of the maintenance mode, a first potential of one of the first electrode and the second electrode operating as the measuring electrode relative to another one of the first electrode and the second electrode operating as the reference electrode, and to set, in a second phase of the maintenance mode, a second potential of the one of the first electrode and the second electrode operating as the measuring electrode relative to the another one of the first electrode and the second electrode operating as the reference electrode.

A process for maintaining an electrochemical fuel cell for measuring ethanol in human breath, wherein the electrochemical fuel cell comprises a first electrode, a second electrode, a third electrode and a control module operatively connected to the electrodes and configured to control the electrodes, wherein the first electrode is provided to be used as a measuring electrode in a regular operating mode of the electrochemical fuel cell and as a measuring electrode or as a reference electrode in a maintenance mode of the electrochemical fuel cell, wherein the second electrode is provided to be used as a counterelectrode in the regular operating mode of the electrochemical fuel cell and as a measuring electrode or as a reference electrode in the maintenance mode of the electrochemical fuel cell, wherein the third electrode is provided to be used as a counterelectrode in the maintenance mode of the electrochemical fuel cell,

• the process comprising:
• operating, with the control module, the electrochemical fuel cell alternatively in the regular operating mode or in the maintenance mode,
• setting, with the control module in a first phase of the maintenance mode, a first potential of one of the first electrode and the second electrode operating as the measuring electrode relative to another one of the first electrode and the second electrode operating as the reference electrode;
• and
• setting, with the control module in a second phase of the maintenance mode, a second potential of the one of the first electrode and the second electrode operating as the measuring electrode relative to the another one of the first electrode and the second electrode operating as the reference electrode.