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AQS Air Quality Sensor

Detects outside air quality and works with HVAC systems to enable intelligent fresh-air control and early pollution response

The AQS air quality sensor uses metal oxide (MOx) gas sensing technology to monitor changes in outdoor pollutant gas concentration through redox reactions on the sensitive layer. It can detect gases such as CO, NO₂, and optional NH₃ in real time. The sensor outputs air quality signals across six levels (0-5) and identifies deteriorating air conditions with a fast response time of ≤20 seconds. The AQS module is typically installed in the front cabin or air intake system to monitor external pollution, exhaust emissions, high-NO₂ roads, tunnels, and similar environments. When air quality declines, it sends a level signal to the vehicle HVAC controller, triggering functions such as closing fresh-air intake, switching to recirculation mode, or improving filtration performance to prevent polluted air from entering the cabin. With high-sensitivity MOx sensing, fast response, and intelligent grading algorithms, the vehicle can detect worsening air conditions in advance and automatically adjust intake strategies, helping create a cleaner and healthier cabin environment.

Key Advantages

High Sensitivity

Built on an optimized MOx semiconductor structure, the sensor offers high sensitivity to gases such as CO and NO₂, with response time ≤20s for real-time air quality detection.

High Consistency

Our proprietary MOx auto-calibration system supports stable mass production and consistent air quality output across vehicles and installation positions.

Automotive-Grade

Designed for stable operation from −40°C to 85°C, with strong resistance to vibration, humidity, and chemical exposure. Temperature compensation helps reduce environmental impact on output.

Low Power, Cost-Efficient

The MOx structure is compact, reliable, and suitable for cost-effective mass production, while offering low power consumption and flexible integration into vehicle intake systems.

Sensor Technology Principle
AQS Sensor Principle Diagram
AQS Sensor Technology Principle Illustration

AQS Series

The AQS air quality sensor detects VOC pollutants in outside air, including typical automotive exhaust gases such as NO₂, NH₃, and CO. Air quality level data is transmitted to the vehicle HVAC system in real time. In heavy traffic, tunnels, exhaust-dense areas, or environments with sudden air quality changes, the system can automatically close fresh-air intake, strengthen recirculation purification, or adjust fan strategy to keep polluted air out of the cabin. With fast response, high sensitivity, and multi-gas capability enabled by MOx sensing technology, AQS helps identify worsening air conditions earlier and respond faster. This solution is especially suitable for scenarios that are sensitive to outside air changes, such as urban congestion, truck-heavy roads, high-NO₂ routes, and tunnel entrances. It helps reduce occupant exposure to harmful gases and improves cabin health, safety, and comfort.

AQS HVAC Integration Illustration
Technical Specifications
AQS Module
Measurement Range
0-50,000 ppm
Power Consumption
Average: 15 mA / Peak: 150 mA / Sleep Mode: <100 μA
Accuracy
±(50 ppm + 3% of reading)
Communication Method
LIN / CAN Communication
Resolution
1 ppm
Service Life
≥15 Years
Warm-Up Time
15 Seconds
Response Time (T90)
< 60 Seconds
Operating Temperature
-20 ~ 70 ℃
Operating Humidity
0-95% RH (Non-Condensing)
Storage Temperature
-30 ~ 70 ℃
Power Supply Voltage
4.5 ~ 6.5 V

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Designed to match module structure and air intake layout, with support for customized clips, sealing structures, and installation methods based on vehicle platform, ensuring optimal placement in the front cabin or intake path for reliable and responsive outside air quality detection.

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