Exhaust gas sensing system and method for determining concentrations of exhaust gas constituents

摘要

An exhaust gas sensing system (28) and a method for determining concentrations of exhaust gas constituents are provided. The exhaust gas sensing system includes a NH3 sensing cell (82) , a NO2 sensing cell (84), a NOx pumping cell (113), and a current sensor (48) that detects an electrical current flowing through the NOx pumping cell (113). A computer (42) determines a NO 2 concentration value, a NH 3 concentration value, a NO concentration value, and a NO x concentration value based on signals from the NH3 sensing cell (82) , the NO2 sensing cell (84), and the current sensor (48).