Abstract: An electrochemical gas sensor including a sensor body having a cavity, an electrolyte in the cavity, an auxiliary electrode in contact with the electrolyte, a sensing electrode in contact with the electrolyte, and a blocking electrode in contact with the electrolyte. At least a portion of the blocking electrode is positioned intermediate the auxiliary electrode and the sensing electrode, and the blocking electrode reduces electroactive materials within the electrolyte. Also disclosed is a method for sensing a partial pressure of a target gas in a sample gas, the method including introducing the sample gas into a gas sensor, applying different potentials to the auxiliary electrode, sensing electrode and blocking electrode, reducing electroactive materials present in the electrolyte to prevent the electroactive materials from contacting the sensing electrode, and outputting an electrical signal from the gas sensor representative of the target gas partial pressure.

Abstract: A device including a flexible circuit disposed within a conductive tube. The circuit may include a flexible substrate and one or more circuit elements. The circuit may have circuit elements on one or both sides, and the substrate may be multi-layered. The tube may have any one of many cross-sectional shapes, including circular, oval, square, and rectangular.