Gravity SFA40 Formaldehyde Sensor

The Gravity SFA40 from DFRobot measures formaldehyde (HCHO) with the electrochemical SFA40 sensor from Sensirion. It hardly reacts to other volatile substances: the cross-sensitivity to ethanol is 0.3 %, and according to DFRobot perfume or oranges do not cause false readings. An SHT4x on the module measures temperature and humidity for compensation and outputs both values as well. It connects via I2C through the Gravity connector.

Important: Do not let the yellow protective film on the sensor come into contact with solvents and do not scratch it. Store the sensor at 0 to 50 °C; according to DFRobot, higher temperatures can permanently raise the baseline.

Note: The connection cable can be converted to male pins with a Dupont cable M-M, so that it also fits an Arduino UNO.

Recommended Accessories:

Dupont Cables M-M 10cm 20 Pieces

Features:

Formaldehyde with detection limit 20 ppb, accuracy ±20 ppb or ±20 % of reading (0 to 200 ppb)
Measuring range 0 to 2000 ppb according to the product page, the wiki states 0 to 1000 ppb
Cross-sensitivity ethanol 0.3 % (15 ppb reading at 5 ppm ethanol)
SHT4x for temperature and humidity compensation, outputs HCHO, temperature and humidity
10 minutes start-up time after switching on, response time below 2 minutes
Very low current: 80 µA on average at 2 Hz
DFRobot_SFA40 library for Arduino, example for Mind+

Application Examples:

Measuring off-gassing of furniture, floors and paints indoors
Controlling ventilation or windows from 80 ppb formaldehyde (value according to DFRobot)
Switching on air purifiers only when needed
Portable measuring device for rooms and vehicles