Particulate matter sensor with improved measurement accuracy

Abstract

The invention relates to the technical field of tail gas emission control of vehicles, and discloses a particulate matter sensor with improved measurement accuracy. The particulate matter sensor is provided with a conductive shell, a cylindrical protective piece and a high-voltage electrode which is arranged in the conductive shell and is insulated from the conductive shell, wherein the conductive shell is grounded; high voltage is applied onto the high-voltage electrode; and a metal shielding layer is arranged in a sealed space and at the periphery of the high-voltage electrode, is grounded and is insulated from the high-voltage electrode. A measurement method for the particulate matter sensor comprises the following steps of: measuring leakage current, capacitance or resistance values between the high-voltage electrode and the conductive shell; and acquiring the concentration of particulate matters in gas to be detected according to a functional relation. The particulate matter sensor with the improved measurement accuracy has high measurement accuracy and long service life; and by the metal shielding layer, interference leakage current is eliminated, and pollutants of which the outside is oxidized and corroded can be prevented from entering an internal space so as not to influence the measurement accuracy and the service life.

Description

technical field [0001] The invention relates to the technical field of vehicle exhaust emission control, in particular to a particle sensor for improving measurement accuracy. Background technique [0002] Diesel vehicles in energy saving and CO 2 There are certain advantages in terms of emission reduction. At the same time, the particulate matter emitted by diesel vehicle exhaust has an impact on the human body and the environment. 80% of particulate emissions are below PM2.5, and large particles are formed by agglomeration of small particles. my country is now strengthening the detection of PM2.5 in preparation for the formulation of stricter emission regulations. At present, European and American countries have widely used particle filters (DPF) on diesel vehicles to remove most of the particles in the exhaust gas. Reliable regeneration and failure monitoring of the DPF system requires on-board diagnostics (OBD). [0003] The OBD emission regulations at home and abro...

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Problems solved by technology

[0007] The technical problem to be solved by the present invention is: in order to overcome the shortcomings of low measurement accuracy and short service life of the particle sensor in the prior art, the present invention provides a particle sensor with improved measurement accuracy. The particle sensor has good sealing effect and long service life , high-voltage electrode measurement, high measurement accuracy

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