What is NOx Sensor--- Product Overview

● NOx sensor is a key part in combustion engine ATS, it measures NOx concentration and communicate with ECU.

● NOx sensor heat up to 25℃ when power on, reached pre heating status.

● When NOx sensor received dew point, element heat up to working temp(~800 ℃)，reached status byte in about 2min.

What is NOx Sensor --- Product Principle

● Exhaust gas which contains H₂O, NO₂, NO and O2 going through 1st cavity by molecular diffusion.

● O₂ was decompensated and pumped out at 1st cavity, NO₂ turn to NO, rest gas go through into 2^nd cavity.

● NO was decompensated into N₂ and O₂ at M₂, NOx concentration was calculated by current accordingly.

What is NOx Sensor --- Product Parameter and Structure

Failure Mode and Action --- NTF

● Failure: MIL light up , error will be eliminated after whole ATS replaced, but original NOx sensor have full functionality.

● Root cause: Operators do not detect right root cause.

● Action: Test NOx will diagnosis device, pls re-use NOx sensor if it has full functionality.

Failure Mode and Action --- Mechanical Damage

● Failure: NOx sensor communication or heating error, obviously damage NOx appearance.

● Root cause: Incorrect operation or violent operation.

● Action: Replace NOx sensor , sensor should be handled following ‘’Maintenance Handbook’’ from OEM.

Failure Mode and Action --- Water Ingress

● Failure: NOx sensor communication error, obviously water ink and rust at customer connector.

● Root cause: Matting connector sealing failure, such like sealing plug or sealing ring missing.

● Action: Replace NOx sensor, pls chose matting connector which meet IP69 sealing class.

Failure Mode and Action --- Element Ceramic Breakage

● Failure: NOx sensor communication error , noise when shaking element.

● Root cause: NOx sensor was broken by huge operation force.

● Action: Replace NOx sensor , sensor should be handled following ‘’Maintenance Handbook’’ from OEM.

Failure Mode and Action --- Element Over Stress

● Failure: NOx sensor communication error, no obviously appearance defect.

● Root cause: Over current loaded at NOx sensor which lead to electronic component broken.

● Action: Replace NOx sensor , double check NOx sensor supply voltage.

Application Note --- Tips

● Do not mass up during storage. Do not knot , bend and warp.

Application Note --- Tips

● Do not painting. Do not washing.

Application Note --- Tips

● Do not open NOx sensor. Do not contact with chemical solvent.

How to Set up a Reliable Application --- Mounting

● Please pay attention to NOx sensor mounting position and layout during development phase.

● Reasonable mounting position will gather typical NOx concentration and improve ATS efficiency.

● To avoid NOx sensor broken during turbulence , please consider about the safely loop design.

How to Set up a Reliable Application --- Mounting

● Please pay attention to gas velocity around NOx sensor mounting position.

● Recommendation gas velocity is between 10 m/s and 60 m/s , and avoid gas trap and condensation area.

How to Set up a Reliable Application --- Dew Point

● Please consider to validate reasonable dew point strategy , which could efficiently avoid element crack.

● Could supply test device and technical support during dew point test.

How to Set up a Reliable Application --- Sensitivity

● NOx sensor have NO₂ , NH3 and pressure sensitivity , please consider signal correction during development phase.

● NOx sensor correction formula embed in SCU , detail solution please contact with engineer.