Exhaust gas sample collector and mixer for aftertreatment system

An exhaust gas treatment system including an exhaust gas pathway configured to receive exhaust gas from an internal combustion engine, the exhaust gas treatment system comprising:

• a treatment device including a housing having an inlet passage and an outlet passage;
• a collar positioned within the outlet passage such that the collar engages an interior wall of the outlet passage, wherein the collar includes an inlet configured to receive a sample of the exhaust gas and an outlet downstream from the inlet, and wherein the collar defines a tortuous pathway from the inlet to the outlet, between the collar and the interior wall;
• and
• a sensor located at the outlet of the collar to measure a characteristic of the sample.

An exhaust gas treatment system including an exhaust gas pathway configured to receive exhaust gas from an internal combustion engine, the exhaust gas treatment system comprising:

• a reductant injector configured to inject a reductant into the exhaust gas pathway;
• a treatment device including an SCR element positioned downstream of the reductant injector, the SCR element configured to reduce NOx from the exhaust gas;
• a sample collector positioned within the exhaust gas pathway, the sample collector including:
• a plurality of inlet openings circumferentially spaced about a periphery of the exhaust gas pathway and configured to receive a sample of exhaust gas from the exhaust gas pathway,
• an outlet in fluid communication with the plurality of inlet openings, and
• a tortuous flow path extending from the plurality of inlet openings to the outlet, the tortuous flow path including a rib located between the plurality of inlet openings and the outlet;
• a NOx concentration sensor located at the outlet of the sample collector to measure a NOx concentration of the sample;
• and
• a controller in communication with the NOx concentration sensor and the reductant injector, wherein the controller is configured to control operation of the reductant injector based on feedback from the NOx concentration sensor.