NOx gas sensor

Abstract

The invention discloses a NOx gas sensor, and belongs to the field of gas sensors. The sensor sequentially comprises a silicon substrate layer, a support layer, a heating electrode, an insulating layer and a test electrode layer from bottom to top, wherein a heat insulation cavity is formed in one side of the test end above the silicon substrate layer; the support layer completely covers the silicon substrate layer; the heating electrode is arranged between the support layer and the insulating layer, and the insulating layer is used for isolating the heating electrode from the test electrode layer; the test electrode layer comprises a second electrode, a first electrode and a third electrode which are arranged in parallel, wherein the first electrode, the second electrode and the third electrode extend from the electrode end to the test end. The first electrode is made of a material sensitive to NOx, the second electrode and the third electrode are made of precious metal, and a three-electrode system is formed. During test, the third electrode is used as a reference electrode, and the polarization voltage of the second electrode can be regulated; and after NOx gas is introduced, the NOx content can be determined by recording the current change between the first electrode and the second electrode.

Description

technical field [0001] The invention belongs to the technical field of gas sensors, in particular to a NOx gas sensor. Background technique [0002] Currently widely used NOx gas sensors include semiconductor type and solid electrolyte type. Among them, the semiconductor-type NOx gas sensor has poor accuracy and is difficult to meet the increasingly harsh use environment; the solid-state electrolyte NOx gas sensor needs to completely decompose NOx into O 2 In the test, the structure of the sensor is complicated, the number of electrodes is large, and the operation is not cheap. Therefore, adjusting the structure of the sensor and changing the operating mode of the sensor are the main technical difficulties of the NOx gas sensor. [0003] Considering the advantages of electrochemical gas sensors in terms of detection accuracy, it is of certain significance to carry out relevant structural design and realize quantitative analysis of sensor detection. In addition, with the r...

AI Technical Summary

Problems solved by technology

Among them, the semiconductor-type NOx gas sensor has poor accuracy and is difficult to meet the increasingly harsh use environment; the solid-state electrolyte NOx gas sensor needs to completely decompose NOx into O 2 For testing, the sensor structure is complex, the number of electrodes is large, and the operation is not cheap

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