Gravity SFA40 Formaldehyde Sensor 0-1000 ppb

The DFRobot Gravity SEN0661 is a high-precision electrochemical formaldehyde sensor based on the Sensirion SFA40, a miniature HCHO sensor element developed and calibrated in Switzerland. Unlike most formaldehyde sensors on the market, the SFA40 shows extremely low cross-sensitivity to other volatile substances: the cross-sensitivity to ethanol is less than 0.3%, and substances like perfume or citrus oils do not trigger false alarms.

Note: After each power-on, the sensor requires 5 minutes of warm-up time for accurate measurement. The yellow ventilation membrane on the SFA40 element must not come into contact with organic solvents and must not be scratched.

Features:

Sensirion SFA40 with extremely low cross-sensitivity (< 0.3% to ethanol) - specifically responds to formaldehyde, not to perfume, citrus, or alcohol
Measurement range 0–1000 ppb HCHO with ±20 ppb accuracy and 20 ppb detection limit for early warning at health-relevant values
Integrated Sensirion SHT4x for automatic temperature and humidity compensation directly on the module - no external compensation calculation
I2C communication via Gravity PH2.0-4P; operating voltage 3.3–5 V; 80 µA average current (@2 Hz), 2 mA peak current
Operating temperature -40 to +125 °C; operating humidity 0–100% RH (non-condensing) for a wide range of applications
Compact size 32 × 22 mm for easy integration into air quality stations and portable measurement devices

Application Examples:

Smart home air monitoring detecting formaldehyde emissions from new furniture, flooring, and wall paints
Automatic ventilation control activating windows or fans when HCHO levels exceed health-relevant 80 ppb
Smart air purifiers activating activated carbon filters only when actual HCHO loads are detected
Portable room air tester for testing various rooms or new vehicles for HCHO emissions
Research and educational applications for indoor air quality studies and climatology with calibrated lab chip

Documentation:

DFRobot Wiki – SFA40 Formaldehyde Sensor

Technical Data:

Manufacturer: DFRobot
Manufacturer SKU: SEN0661
Sensor Chip: Sensirion SFA40
Measurement Principle: Electrochemical (HCHO-specific)
Measurement Parameters: Formaldehyde (HCHO), temperature, relative humidity (SHT4x onboard)
HCHO Measurement Range: 0–1000 ppb
HCHO Measurement Accuracy: ±20 ppb
HCHO Detection Limit: 20 ppb
Cross-Sensitivity Ethanol: < 0.3%
Interface: I2C (Gravity PH2.0-4P)
Operating Voltage: 3.3–5 V
Operating Current: 80 µA (average @ 2 Hz), 2 mA (peak)
Operating Temperature: -40–+125 °C
Operating Humidity: 0–100% RH (non-condensing)
Warm-Up Time: 5 minutes after power-on
Product Dimensions: 32.0 × 22.0 mm
Packaging Dimensions: 61 × 56 × 25 mm
Gross Weight: 13 g