Gravity: SFA40 Formaldehyde (HCHO) Sensor | ±20 ppb High Accuracy | Anti-Interference Electrochemical Monitor | Built-in SHT4x Temp/Humidity Compensation | I2C for Arduino/ESP32 IAQ

SFA40 Formaldehyde (HCHO) Sensor IntroductionThe Gravity: SFA40 HCHO Sensor is a high-precision electrochemical module designed to solve the biggest pain point in air quality monitoring: false alarms. Powered by the industry-leading Sensirion SFA40 chip, this formaldehyde detector specifically targets HCHO molecules while ignoring common household odors like alcohol or perfumes. Featuring a built-in SHT4x sensor for automatic temperature and humidity compensation, this monitoring unit delivers reliable data for smart home devices, HVAC systems, and DIY air purifiers. Specification High accuracy: Error ±20 ppbWide measurement range: 0–1000 ppb Low cross-sensitivity: Cross-sensitivity to ethanol ＜0.3%Supply Voltage: 3.3–5V Operating Temperature: -40 to +125 ℃ Operating Humidity: 0–100% R.H. (non-condensing)Operating Current: 80μA(Average@2Hz), 2mA(peak)Size: 32 * 22mm Shipping listGravity: SFA40 HCHO Sensor x1 Gravity 4pin sensor cable x1

• REVOLUTIONARY ANTI-INTERFERENCE & ZERO FALSE ALARMS: Powered by the industry-leading Sensirion SFA40 chip, this electrochemical sensor features a specialized chemistry that specifically filters out ethanol (alcohol) and household odors. Unlike cheap sensors that spike from perfumes or hand sanitizers, the SFA40 ensures your HCHO readings are true and reliable for precise indoor air quality (IAQ) monitoring.
• LAB-GRADE SENSITIVITY & WIDE DETECTION RANGE: Detect formaldehyde levels as low as 20 ppb (parts per billion) with an impressive accuracy margin of ±20 ppb. With a measurement range of 0–1000 ppb, it is sensitive enough to capture trace off-gassing from new furniture, carpets, and paints, making it a professional-grade tool for home safety and renovation checks.
• INTEGRATED SHT4x TEMP & HUMIDITY COMPENSATION: The module features an onboard SHT4x sensor that provides real-time environmental data. More importantly, it uses this data to automatically calibrate and compensate for HCHO readings, preventing data drift caused by varying temperature or moisture levels—ensuring stability in humid basements or dry offices.
• EASY GRAVITY I2C INTERFACE & DEVELOPER READY: Designed for the DFRobot Gravity ecosystem, this sensor offers a plug-and-play 4-pin I2C interface—no soldering required. Fully compatible with Arduino, ESP32, and Raspberry Pi (3.3V-5V). DFRobot provide comprehensive wiki tutorials and libraries, allowing makers and engineers to deploy professional IAQ projects in minutes.
• ULTRA-LOW POWER & COMPACT INTEGRATION (32*22mm): Featuring a tiny footprint of just 32 * 22mm, this module is engineered for seamless integration into space-constrained IoT enclosures and portable devices. With an ultra-low average operating current of only 80μA, it is the perfect choice for battery-powered air quality loggers and smart home nodes where long-term efficiency and a compact form factor are critical.