PM + CO₂ + NTC Automotive Air Quality Sensor - S21

MAXMAC S21 is an automotive-grade multi-in-one air quality sensor designed for intelligent cabin air quality monitoring and automotive HVAC control. It integrates PM2.5, CO₂ and NTC temperature & humidity detection to monitor in-cabin particulate matter, carbon dioxide concentration and environmental changes in real time. The sensor provides reliable data support for fresh air ventilation, air recirculation control, cabin comfort adjustment and automotive air purification systems.

Featuring laser scattering PM2.5 detection, NDIR CO₂ sensing and CMOSens temperature & humidity measurement technology, S21 supports LIN communication and 9–16V vehicle power input. With a wide operating temperature range of -40°C to 85°C, it delivers stable performance in complex automotive environments.

  • Integrated PM2.5 + CO₂ + temperature & humidity detection reduces system complexity
  • PM2.5 measuring range: 0–999 μg/m³, resolution 1 μg/m³
  • CO₂ measuring range: 400–9,999 ppm, resolution 1 ppm
  • Temperature range: -20°C to 85°C; humidity range: 1–99%RH
  • Automotive-grade design with LIN communication and -40°C to 85°C operation
PM + CO₂ + NTC Automotive Air Quality Sensor - S21
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Sensor Technology Principle
All-in-One Sensor Principle Diagram
All-in-One Sensor Principle Diagram
Technical Specifications
S21 3-in-1 Automotive Sensor
Product Name
S21 3-in-1 Automotive Sensor
Integrated Parameters
PM2.5 + CO2 + NTC / temperature-humidity
Operating Voltage
9-16 VDC
Operating Current
Average 80 mA @ 13.5VDC; peak 350 mA @ 13.5VDC
Operating Environment
-40°C to 85°C, 5%-95%RH, non-condensing
Storage Environment
-40°C to 85°C, 5%-95%RH, non-condensing
Service Life
30000 h
Noise
≤25 dB(A) @ 50 cm
Communication
LIN
Overall Dimensions
88.8 mm × 65 mm × 16 mm
Main Body Dimensions
65 mm × 54 mm × 28 mm
PM2.5 Principle
Laser scattering technology
PM2.5 Range
0-999 µg/m³
PM2.5 Resolution
1 µg/m³
PM2.5 Accuracy
≤100 µg/m³: ±15 µg/m³; >100 µg/m³: ±15%
CO2 Principle
NDIR infrared technology
CO2 Range
400-9999 ppm
CO2 Resolution
1 ppm
CO2 Accuracy
±(50 ppm + 5% of reading)
Temperature Principle
CMOSens principle
Temperature Range
-20°C to 85°C
Temperature Resolution / Accuracy
0.1°C; ±2°C
Humidity Principle
CMOSens principle
Humidity Range
1-99%RH
Humidity Resolution / Accuracy
0.1%RH; ±5%RH
Applicable Equipment
  • Intelligent Cabin Air Quality Management System
  • Automotive HVAC Air Recirculation Control System
  • EV Thermal Management System
  • In-Cabin CO₂ Monitoring System
  • In-Cabin and Ambient PM2.5 Monitoring System
  • Automotive Air Purification System
  • Passenger Car HVAC Control System
  • Commercial Vehicle Cabin Environment Monitoring System
Applications
In-Vehicle Air Purification / Intelligent Cockpit

In-Vehicle Air Purification / Intelligent Cockpit

MAXMAC's automotive-grade multi-in-one sensor module integrates PM particulate detection, CO₂ concentration monitoring, and NTC temperature collection for intelligent vehicle cabin air quality management systems. With high-precision sensing units and a stable signal processing architecture, it enables synchronized multi-parameter acquisition and real-time output, providing reliable data for intelligent cockpits and automotive air purification systems.

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