Standard gas for motor vehicle exhaust testing

Vehicle exhaust gas detection refers to the analysis and determination of the component and concentration of exhaust gas emitted by gasoline and diesel vehicles during the regular annual inspection of vehicle exhaust gas detection. The detection items mainly include the detection of hydrocarbons, carbon oxides (CO, CO2), nitrogen oxides (NO, NO2) photochemical oxidants and smoke, etc. If the detection meets the national exhaust emission standards, the vehicle can continue to run.

Since May 1, 2019, China has officially implemented the new environmental protection standards for vehicle exhaust testing:

• GB18285-2018 Gasoline Vehicle Exhaust Pollutant Emission Limits and Measurement Method (Double Idle Method and Simple Working Condition Method)
• GB 3847-2018 Diesel Vehicle Pollutant Emission Limits and Measurement Methods (Free Acceleration Method and Load Deceleration Method)

Compared with the old standard, the new standard brings some significant changes:

• Increase the type of exhaust pollutants that need to be tested: determination of nitrogen oxides;
• The limit value of C3H8, the original four-in-one pollutant in gasoline line, was reduced by 6 times.
• The calibration frequency of the new national standard for standard gas inspection is increased to once every 24 hours.

The principle of calibration is high standard and low inspection. The specific operation and evaluation are as follows:

Standard gas composition for motor vehicle exhaust testing