Patent ID: 9128045
Filing Date: 2015-09-08
Classification: G01N

Abstract:
1. An analytical instrument, comprising: (a) an electrochemical sensor for sensing a target analyte in a test volume, the electrochemical sensor comprising a single sensing electrode and a single counter electrode, both in contact with a common electrolyte and a common test volume, for generating an electrical current proportional to the concentration of target analyte present in the test volume, (b) a signaling module in electrical communication with the electrochemical sensor for receiving electrical current generated by the electrodes and producing an electrical output signal proportional to the electrical current, (c) a normally open switch for providing an electrical short circuit between the single sensing and single counter electrodes when closed, whereby electrical current generated by the electrodes bypasses the signaling module when the switch is closed, and (d) a microprocessor containing a span calibration value and a zero calibration value in memory, the microprocessor in electrical communication with the signaling module and the switch wherein: