At the recently concluded 11th NEAS CHINA 2023, "CHINA 6b" commercial vehicles and related accessories became a major focus. In line with this, China's commercial vehicle market sales improve this year, realizing "9 consecutive growths" since February,which is telling the good news of the market's continuous recovery with sales figures.
Policy Background: Commercial Vehicle Emission Standards Raised Again
In May, a total of five departments, including the Ministry of Ecology and Environment and the Ministry of Industry and Information Technology, jointly issued Announcement on Matters Relating to the Implementation of National VI Emission Standards for Motor Vehicles, which stipulates that since July 1, the National VI Emission Standard Stage 6b will be fully implemented on a nationwide basis, and that the production, import, and sale of automobiles not complying with the National VI Emission Standard Stage 6b will be prohibited.
From the market data, "CHINA 6b" emission standards, although strict, but did not repel the market confidence, mainly because the industry has mature pollutant emission limits and measurement methods to deal with.
SCR system: the core system for exhaust emissions treatment
The "CHINA 6b" emission standard sets lower emission limits for the original pollutants such as nitrogen oxides, particulate matter mass (PM), carbon monoxide, hydrocarbons, etc., while new emission limits for pollutants such as particle number (PN) and ammonia have been added, which has substantially increased the exhaust emission requirements for diesel engines. Therefore, the SCR system has become more important as one of the core systems for handling pollutant emissions.
Ultrasonic Adblue Quality Sensor : a necessary sensing component of SCR system for commercial vehicles
According to the "CHINA 6b" standard, commercial vehicles are required to adopt a "Driver Alert System" and a "Driving Performance Limitation System", which are designed to monitor exhaust emissions in real time, ensure that the treatment system works properly, and ensure that the output of the exhaust gas meets the emission standards.If the diesel engine unit of a commercial vehicle does not have an exhaust gas treatment fluid added, or if the exhaust gas treatment fluid is of insufficient purity or low quality, the system will transmit the problems found directly to the relevant regulatory authorities, and at the same time inform the driver to repair the unit as soon as possible, and the engine of the vehicle with the problem will be subject to torque and speed limitations.On the other hand, poor-quality diesel exhaust treatment fluids can contaminate the catalyst in the catalytic unit of the SCR system, with serious consequences.Therefore, a reliable Ultrasonic Adblue Quality Sensor is essential sensing components for SCR systems.
For this reason, AUDIOWELL has launched the Ultrasonic Adblue Quality Sensor specifically for SCR system urea detection, the product with matching circuit, you can real-time monitoring of the quality of automotive urea, high reliability and good consistency. Currently, ultrasonic measurement solutions are the dominant technical solutions in the market for testing urea quality.
Working principle of Ultrasonic Adblue Quality Sensor
On the one hand, the different propagation speeds of ultrasonic waves in different media are used to determine whether it is a urea solution or not, and on the other hand, the propagation speeds of ultrasonic waves in different concentrations of urea solutions are used to determine whether the urea solution meets the standard or not. The Ultrasonic Adblue Quality Sensor emits ultrasonic waves and also receives an echo signal. It calculates the TOF time of the ultrasonic waves at a fixed distance in the liquid, and comparing the time difference, it can know the difference value of the liquid concentration, and according to this difference value, whether it is a urea in compliance with the regulations or not.
Ultrasonic principle of the formula: S = V - T / 2 (S: ultrasonic signal distance traveled, V: speed of sound ∝ concentration, T = receiving time - sending time, the difference in T that is, the difference in the quality of urea)
Figure 1: Difference in propagation time of ultrasound in different media
Comparison of the change in propagation velocity with increase in temperature for 32.5% urea solution (red) and pure water (green)
Due to the different propagation speeds of ultrasonic waves in different media, combined with the above figure, fitting the corresponding functional equation, it can be concluded that: in a fixed distance, the time difference can be recognized whether the measured liquid is 32.5% urea solution or not.
Figure 2: Difference in propagation time of ultrasonic waves at different concentrations in the same medium
As shown in Figure 2, different concentrations of urea solutions in the same temperature with different propagation speeds, fitting the corresponding functional equation, it can be learned that: in a fixed distance, the time difference can be identified by the measured liquid is a compliant concentration of urea solution.
High reliability and stable signal
Ultrasonic Adblue Quality Sensor can maintain a stable signal output in both high-frequency vibration and low-frequency vibration environments, and can promptly alert the driver whether the urea concentration in the urea tank meets the standard requirements, with the aim of ensuring that the vehicle's exhaust emissions comply with the requirements of the "CHINA 6b" and more stringent emission regulations.
The product adopts all-metal sealing design and reaches IP68K/IPX7/IPX9K waterproof grade requirements, which can meet the use conditions of various extreme working conditions of vehicles. At present, Ultrasonic Adblue Quality Sensor has passed the reliability requirements of many domestic vehicle manufacturers.
Superior performance, leading the industry level
Ultrasonic Adblue Quality Sensor can be compatible with the mainstream software program in the market. AUDIOWELL's R&D team has mastered a number of core technologies related to urea quality testing, with an effective signal to clutter ratio of up to 6.0, and leading industry performance.
Good consistency and quality
AUDIOWELL has passed ISO9001, IATF16949 and other quality management system certifications, and strictly follows the system requirements. The consistency of the products is good, and the quality of the products meets the requirements of SCR system parts suppliers.
Provide product customization services and full process services
The probe structure of the sensor can be customized according to customer requirements, and it is compatible with various urea tanks and various urea sensor assemblies. AUDIOWELL provides the whole process of product design, testing and production services to meet the high precision needs of urea quality testing for commercial vehicle SCR systems.