Core Component of Smart Environmental Monitoring

In today's pursuit of healthy and sustainable living, indoor air quality has become a key concern. Pollutants such as volatile organic compounds (VOCs) and carbon monoxide (CO) are often invisible in homes, offices, and vehicles, and prolonged exposure may cause respiratory issues or more severe health risks. With over 40 years of experience in gas sensor technology, Nexisense has been dedicated to exploring and applying advanced sensing technologies. The SGP90, a multi-channel gas sensor, provides high-efficiency detection and integrated design, making it a reliable core for smart environmental monitoring. This article introduces its working principle, technical features, comparison with the SGP30, advantages, and real-world applications, helping readers fully understand its value and explore effective project deployment. These insights demonstrate how SGP90 drives smart air quality management.

Core Principle of the SGP90 Sensor

The SGP90, developed by Sensirion, is a digital multi-gas sensor based on metal oxide semiconductor (MOS) technology, designed for high-precision, low-power multi-parameter monitoring. Its detection relies on a metal oxide thin film (e.g., SnO₂) interacting with target gases under heating: when VOCs or CO molecules contact the film surface, a redox reaction occurs, changing the film’s resistance. This change is measured by precise circuitry and converted into concentration values using built-in algorithms.

The sensor features two independent channels: one for VOCs (e.g., ethanol, formaldehyde) and one for CO. Reactions occur under controlled micro-heating at 200-400°C, ensuring activity without excessive energy consumption. The digital output uses an I²C interface, delivering calibrated concentration data directly, simplifying system integration.

SGP90’s integration is another highlight: it includes a high-precision temperature and humidity sensor to compensate for environmental variations in real-time, avoiding measurement deviations caused by temperature fluctuations. Smart algorithms further process the raw signal for reliable readings. Low-power mode supports energy-efficient sampling, with average power consumption of only a few milliwatts, suitable for battery-powered devices. Nexisense ensures stable data transmission when deploying SGP90 in IoT platforms.

This principle enables SGP90 to perform well in complex environments, such as humid or temperature-variable home spaces, still providing accurate VOC and CO concentrations.

Performance Comparison: SGP90 vs. SGP30

The SGP90 is an upgraded version of the SGP series. Compared with the SGP30, which detects VOCs and hydrogen with I²C output but requires external temperature and humidity compensation and has slightly higher power consumption, the SGP90 introduces dual-channel detection, simultaneously monitoring VOCs and CO for more comprehensive assessment. Built-in temperature and humidity sensors improve accuracy, and power consumption is optimized for portable applications. In typical scenarios, SGP90 performs excellently in high-end smart homes, while SGP30 suits standard fresh-air systems.

SGP90 also offers a wider detection range and improved stability via automatic baseline calibration to prevent long-term drift. Nexisense projects show that its integrated design shortens development cycles by over 20%.

Technical Advantages of SGP90

SGP90 combines multiple technical advantages. The dual-gas detection replaces multiple modules, reducing system complexity and saving space. Its DFN package (3.0mm × 3.0mm) is easy to embed in compact devices.

High integration is another key: built-in pre-processing algorithms output calibrated values directly. Temperature and humidity compensation maintains accuracy from -40°C to 85°C. Long-term stability is achieved via baseline calibration, automatically adjusting the zero point even in polluted environments, with a lifespan of 5-10 years.

Low-power design supports modes such as low-frequency sampling, suitable for wearable or IoT devices. Nexisense leverages these features to develop custom solutions for efficient deployment.

Typical Application Scenarios

SGP90’s practicality spans multiple scenarios. In smart home systems, it monitors indoor VOCs and CO, triggering ventilation or alarms if concentrations exceed thresholds (e.g., VOCs >500ppb), improving comfort. In air purifiers, it evaluates purification effectiveness, switching modes intelligently and saving over 30% energy when CO levels rise. Nexisense solutions are integrated into multiple purifiers with positive user feedback.

In vehicles, SGP90 monitors cabin pollutants, providing alerts, especially for CO during heavy traffic. Portable air quality devices leverage its low power for mobile monitoring. In smart controllers, it links with apps for data visualization and remote management, demonstrating multifunctionality and driving industry innovation.

Nexisense Technical Support

Nexisense provides full support for SGP90 deployment, including application design with reference circuits and PCB layout recommendations for smooth integration. Algorithm support includes drivers and base algorithms for rapid development. Custom services allow gas-specific calibration optimization for particular VOCs. Experienced teams assist from prototype to mass production, reducing risks.

FAQ

1. How does the SGP90 sensor work? It is MOS-based, where gas reactions change resistance, producing concentration outputs.

2. Which gases can it detect? VOCs (ethanol, formaldehyde) and CO via independent dual channels.

3. What upgrades does SGP90 have over SGP30? Added CO channel, built-in temperature/humidity compensation, ultra-low power, dual-gas detection.

4. What output interface does it use? I²C digital interface with calibrated concentration output.

5. Typical sensor lifespan? 5-10 years with baseline calibration, depending on environment.

6. How to use low-power mode? Supports energy-efficient sampling for battery-powered devices.

7. What support does Nexisense provide? Design reference, algorithm library, custom calibration development.

8. Is SGP90 suitable for vehicles? Yes, compact and low-power ideal for in-cabin air monitoring.

9. How is drift managed? Automatic baseline calibration ensures long-term stability.

10. What to consider when integrating SGP90? I²C bus compatibility and stable power supply to avoid interference.

Conclusion

The SGP90 gas sensor, MOS-based with dual-channel detection and integrated design, is a pillar for smart environmental monitoring. Compared to previous generations, it excels in accuracy, stability, and low power, widely applied in homes, purifiers, and IoT devices. Nexisense provides technical support for practical deployment. In an era where air quality is crucial, this component is not just a technical element but a health guardian. Choosing the right solution significantly improves monitoring efficiency and supports sustainable living.