Electrostatic vehicle exhaust particle sensor for the evaluation of the diesel particulate filter (DPF)

Abstract

A real-time electrostatic particle sensor has been developed to measure the concentration of soot in diesel exhaust. Based on the Venturi effect, the self-priming sampling probe of the sensor was designed to generate a pressure difference to drive particles into the detection region of the electrostatic trap. A detection module was developed for real-time measurement of the nanoamp current generated by charged soot within the probe. The microcurrent was amplified by the signal processing system of the sensor. To guarantee the precision of particles, it was essential to test the performance. The sensor was able to measure currents from −100 nA to −30 nA with a relative error of −0.01%. In addition, experiments comparing the sensor with a commercial instrument have shown that they correlate well. Furthermore, the standard deviation of the sensor was 0.001049 during a 36 h long-term test, which is lower than a commercial instrument with better stability. The sensor was investigated to demonstrate the detection of diesel particulate filter (DPF) failure. The results showed that the consistency between the sensor and the regulatory measurement equipment was good. The data ratios of the sensors installed at the front and rear of the DPF differed by many fold, which indicated that the sensor was able to determine the status of the exhaust system.

Keywords:

• Diesel exhaust particles
• diesel particulate filter (DPF) failure
• particulate matter (PM) sensor

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Key R&D Program of China under Grant 2023YFC3705400, Natural Science Foundation of Anhui Province under Grant 2208085MF162, Plan for Anhui Major Provincial Science Technology Project under Grant 202203a07020004, National Natural Science Foundation of China under Grant U2133212, and the Key Research and Development Plan of Tianjin under Grant 22YFYSHZ00260.