Gravity: SFA40 Formaldehyde (HCHO) Sensor (0–1000 ppb, High Accuracy ±20 ppb)

Gravity: SFA40 HCHO Sensor is a high‑precision electrochemical module built for accurate formaldehyde monitoring in indoor environments. Powered by the Sensirion SFA40 sensing chip, this Gravity‑series air quality sensor selectively detects HCHO molecules while minimizing interference from common household vapors such as alcohol or perfumes. Integrated SHT4x temperature and humidity sensing enables automatic environmental compensation, delivering stable and reliable readings for air monitoring systems. With a convenient Gravity I2C interface compatible with Arduino platforms and other development boards, this environmental sensing module integrates easily into smart home projects, HVAC monitoring equipment, and experimental air‑quality instrumentation.

Zero False Alarms with Selective Electrochemical Detection

Traditional gas sensors frequently produce false alerts when exposed to harmless household scents such as citrus oils, cleaning products, or hand sanitizer. This electrochemical formaldehyde detection module addresses that challenge through advanced electrode materials engineered for extremely low cross‑sensitivity to ethanol (below 0.3%). Such selective detection ensures that rising measurements correspond to genuine formaldehyde concentration changes rather than background odors, making this indoor air quality monitoring board suitable for reliable safety alerts and environmental diagnostics.

Figure: Advanced Electrochemical Principle for Specific HCHO Detection

Laboratory‑Grade Sensitivity Down to 20 ppb

Detecting trace‑level formaldehyde requires extremely high sensing resolution. This precision HCHO monitoring module provides a detection threshold as low as 20 ppb, enabling identification of subtle off‑gassing from building materials, furniture coatings, or interior finishes. Such sensitivity allows environmental researchers, air‑quality developers, and safety monitoring systems to capture concentration changes that many conventional gas sensors overlook. Accurate trace detection makes this air pollution measurement unit suitable for both residential monitoring devices and laboratory‑level experimental setups.

Figure: Ultra-high Sensitivity: Detecting 20ppb is like finding 20 grains in 15 tons of rice.

Integrated Temperature and Humidity Compensation

Environmental conditions such as heat and humidity can introduce measurement drift in gas sensing systems. This formaldehyde sensing board integrates an onboard SHT4x environmental sensor that continuously measures ambient temperature and humidity, enabling automatic real‑time compensation. Such embedded calibration maintains measurement stability across different environments including humid basements, residential living spaces, and office interiors. Simultaneous monitoring of HCHO concentration, temperature, and humidity also provides a richer environmental data set for smart air monitoring platforms.

Figure: Real-time Output: Simultaneous HCHO, Temperature, and Humidity Monitoring.

Figure: Plug-and-Play Gravity I2C Interface with Arduino.

This electrochemical air quality module enables accurate formaldehyde monitoring for a wide range of environments including homes, laboratories, and smart buildings. Integration into air purifiers, ventilation controllers, and indoor environmental monitoring stations allows automatic response when HCHO concentrations increase. Such capability supports safer living spaces, energy‑efficient ventilation control, and experimental indoor air research projects.