A tubular NOx sensor

Abstract

The invention provides a tubular NOx sensor, which includes a heating shell, a base, a diffusion barrier and a sleeve, the base includes a bottom plate and an intake pipe, the heating shell is fixed on the bottom plate and the intake pipe is inserted into the heating shell, and the diffusion barrier is fixed on the upper end of the intake pipe , the sleeve is set on the diffusion barrier, the diffusion barrier is a honeycomb coal cylinder, the base and the sleeve are made of zirconia, the outer wall of the intake pipe is provided with the lower section of the positive electrode of the main pump electrode, the lower section of the negative electrode of the main pump electrode, the lower section of the auxiliary pump electrode and Reference electrode, the sleeve is provided with the upper section of the positive electrode of the main pump electrode, the upper section of the negative electrode of the main pump electrode and the upper section of the auxiliary pump electrode, the upper section and the lower section of the positive electrode of the main pump electrode are connected, the upper section and the lower section of the negative electrode of the main pump electrode are connected, the upper section and the lower section of the auxiliary pump electrode are connected, The inner wall of the heating shell is not in contact with the intake pipe and the sleeve, and the inner wall of the intake pipe is provided with a reference electrode. The beneficial effect of the present invention is to solve the problem that the heater and the sensitive element are integrated in the existing nitrogen oxide sensor, and the leakage of the heater affects the measurement sensitivity.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a tube-type NOx sensor. Background technique [0002] At present, the exhaust gas nitrogen oxide sensor chip for vehicles is composed of six layers of zirconia substrates, including three electrochemical oxygen pumps, two chambers, a reference air channel, a heating resistor, leads and eight pins The three electrochemical oxygen pumps are the main pump, the auxiliary pump and the measuring pump, the main pump is in the first chamber, the auxiliary pump and the measuring pump are in the second chamber, and there is a narrow gap between the first chamber and the second chamber. The joints are used to measure the content of nitrogen oxides in the exhaust gas through the joint work of three pumps. [0003] The working principle of this nitrogen oxide sensor chip is that the exhaust gas of the vehicle is introduced into the first chamber through the air inlet, and oxygen is pumped ou...

AI Technical Summary

Problems solved by technology

Due to the high working temperature of the sensor, the heater and the sensitive part of the sensor are co-sintered as a whole, the zirconia substrate is a thin sheet, the circuit design is complex, the volume is small, there is a heating resistor leakage problem, which affects the measurement sensitivity, and there are difficulties in manufacturing, Disadvantages of complex preparation process

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