SKU: SENS-0754
📋 GST Invoice Available

DFRobot Gravity SFA40 HCHO Sensor (0–1000 ppb Wide Range, High Accuracy ±20 ppb) - I2C Interface

₹6,609.00 (Inclusive of all taxes)
Out of Stock

The DFRobot Gravity SFA40 is a high-precision electrochemical formaldehyde (HCHO) sensor module with a 0–1000 ppb range and ±20 ppb accuracy. Featuring an integrated SHT4x for temperature and humidity compensation, it connects via a plug-and-play Gravity I2C interface for seamless integration with Arduino, Raspberry Pi, ESP32, and other 3.3V/5V microcontroller platforms.

Features

  • High-precision electrochemical sensing for formaldehyde (HCHO) with a wide 0–1000 ppb measurement range.
  • Excellent accuracy of ±20 ppb and a low detection limit of 20 ppb for sensitive monitoring.
  • Integrated SHT4x sensor provides automatic temperature and humidity compensation for stable readings.
  • Minimized cross-sensitivity to common interferents like ethanol (<0.3%) for reliable performance.
  • Plug-and-play Gravity I2C interface (3.3–5.5V) for easy connection to Arduino, Raspberry Pi, and other MCUs.

Out of stock

Description

The DFRobot Gravity SFA40 HCHO Sensor is engineered around the Sensirion SFA40 electrochemical sensing element, providing specific and reliable detection of formaldehyde vapor. Its core principle involves a gas-permeable membrane and an electrochemical cell that generates a current proportional to the HCHO concentration, ensuring high selectivity and long-term stability.

To maintain accuracy across varying environmental conditions, the module incorporates a Sensirion SHT4x digital sensor for real-time temperature and humidity compensation. This design mitigates measurement drift, making it suitable for continuous monitoring applications in indoor air quality systems, smart HVAC controls, and portable health devices.

Key Features

  • High-accuracy electrochemical formaldehyde sensor with ±20 ppb precision.
  • Wide operational range from 0 to 1000 ppb (parts per billion) of HCHO.
  • Ultra-low 20 ppb detection threshold for early warning capability.
  • Integrated digital temperature and humidity sensor (SHT4x) for automatic environmental compensation.
  • Specially designed for low cross-sensitivity to ethanol (<0.3%) and other common VOCs.
  • Gravity-series I2C interface with 3.3–5.5V wide voltage input for easy prototyping.
  • Compact PCB footprint (32mm x 22mm) for integration into space-constrained designs.
  • Optimized performance-to-cost ratio for professional air quality monitoring projects.

Applications

  • Indoor air quality (IAQ) monitors and smart home environmental control systems.
  • Automated ventilation and air purifier control based on real-time formaldehyde levels.
  • Portable health and safety devices for personal exposure monitoring.
  • Building management systems (BMS) for office and school air quality assessment.
  • Laboratory and research equipment for precise VOC measurement and analysis.

Technical Specifications

Item TypeGas Sensor Module
Model Number / NameSFA40
Detection GasFormaldehyde (HCHO)
Measurement Range0–1000 ppb
Accuracy±20 ppb
Low Detection Limit20 ppb
Ethanol Cross-Sensitivity< 0.3%
Operating Voltage3.3 – 5.5 V DC
Current Consumption0.08 mA (typical)
InterfaceI2C (Gravity 4-pin)
Operating Humidity0–100% RH (non-condensing)
Compensation SensorIntegrated SHT4x (Temperature & Humidity)
Length32 mm
Width22 mm
Weight4 g

Frequently Asked Questions

What is the operating voltage range for the SFA40 sensor?

The SFA40 module operates from 3.3 to 5.5 volts DC, making it directly compatible with common 3.3V and 5V logic systems like Arduino Uno, ESP32, and Raspberry Pi. Its low current consumption of approximately 0.08 mA allows for efficient battery-powered operation in portable monitoring devices.

How do I connect and communicate with this sensor?

The sensor uses a standard I2C interface via the DFRobot Gravity 4-pin connector. Simply connect the cable to the module and a compatible Gravity I2C port on a DFRobot shield, or wire the standard I2C pins (SDA, SCL, VCC, GND) directly to your microcontroller. The provided libraries for Arduino and Raspberry Pi simplify data reading and calibration.

Does the sensor require calibration, and how is cross-sensitivity handled?

The sensor is factory calibrated for formaldehyde detection. Its electrochemical design and advanced algorithm provide high specificity, with cross-sensitivity to ethanol rated at less than 0.3%. The integrated SHT4x sensor provides automatic temperature and humidity compensation to maintain accuracy without user intervention in typical indoor environments.

What is the typical response time and lifespan of the sensor?

The sensor provides a fast response to changes in formaldehyde concentration. As an electrochemical sensor, its operational lifespan is several years under normal indoor conditions. For optimal long-term accuracy, it is recommended to avoid exposure to condensing humidity and high concentrations of solvent vapors.

Package Includes

  • 1 x DFRobot Gravity SFA40 HCHO Sensor Module
  • 1 x Gravity 4-pin Sensor Cable

Additional Information

Weight 0.004 kg
Dimensions 3.2 × 2.2 cm