SFA30 Formaldehyde Sensor Module
Formaldehyde Sensing Made Easy
The SFA30 is Sensirion’s new digital formaldehyde sensor designed for easy integration into air purifiers, demand-controlled ventilation systems, or indoor air quality monitors.
Based on Sensirion’s electrochemical technology, the SFA30 offers excellent formaldehyde sensing performance with a uniquely low cross-sensitivity to other VOCs. The sensor module’s on-board SHT sensor provides accurate humidity and temperature readings and enables a fully temperature/humidity compensated and factory calibrated formaldehyde concentration output in ppb. Selectable digital UART and I2C interface options, a standard electrical connector, and versatile mounting options make the integration easy. Relying on Sensirion’s experience in environmental sensing and a patented electrochemical cell with anti-dry technology, the SFA30 offers excellent long-term stability and 6 years service lifetime.
Features and Applications
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Sensor Specifications
| Name | Sensor Output | Formaldehyde accuracy | Supply Voltage Range | Interface | Size (LxWxH) mm | Datasheet | Buy |
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| SFA30 | Formaldehyde concentration in ppb, Relative humidity in %, Temperature in °C | ±20 ppb or ±20% of measured value, whichever is larger | 3.3 V or 5.0 V (3.15 - 5.5 V) | I2C / UART | 46 x 24 x 5.5 mm3 | Download |  |
Technology and Benefits
| Technology | Benefits |
|---|---|
| Patented electrochemical cell with anti-dry technology | Excellent long-term stability and 6 years service lifetime |
| Integrated SHT humidity and temperature sensor | On-board RH and T compensation, additional RH and T Output |
| Uniquely low cross sensitivity to other VOCs | Reliable Formaldehyde measurements in real life conditions |
| Fully factory calibrated module | Easy to use and life-time calibrated |
Start Evaluating the SFA30 Today
The SEK-SFA30 evaluation kit has been designed for easy evaluation of Sensirion’s SFA30 formaldehyde sensor. In addition to the SFA30 sensor module, the SEK-SFA30 comes with a UART-USB cable for a plug-and-play connection to a PC and evaluation with Sensirion’s easy-to-use SEK-ControlCenter viewer software. For connecting the sensor to prototyping platforms such as Arduino or RaspberryPi, a 7-pin jumper wire cable is provided.
More information (documentation, drivers, tutorials, etc.) can be found here: www.sensirion.com/my-sfa-ek
Compile your own environmental sensing evaluation kit at: www.sensirion.com/sek
What is Formaldehyde?
Formaldehyde (chemical formula H2-C=O or often HCHO) is a colorless gas and the simplest organic molecule containing C, O, and H. It is highly reactive and has several natural and man-made sources. Formaldehyde concentrations are much higher indoors than outdoors and hence formaldehyde is qualified as a very specific indoor pollutant.
In homes, frequent sources include combustion processes such as smoking, cooking on gas stoves, use of kerosene space heaters, or candle and incense burning. In non-smoking environments, the main sources seem to be construction materials and consumer products. Formaldehyde, by itself or in combination with other chemicals, serves a number of purposes in manufactured products. For example, it is used to add permanent-press qualities to clothing and draperies, as a component of glues and adhesives, and as a preservative in some paints and coating products. Formaldehyde is also found in cosmetics such as liquid soaps, shampoos, or nail varnish.
The most significant sources of formaldehyde are likely to be pressed wood products such as particleboard, plywood, or medium-density fiber board (MDF) made using formaldehyde-based resins. These materials are frequently used as sub-flooring and shelving and in cabinetry and furniture. Elevated formaldehyde concentrations can be present in freshly built, furnished, or painted rooms for months.
Health effects
In relevant concentrations, formaldehyde is a pungent-smelling gas, can cause watery eyes, burning sensations in the eyes and throat, nausea, and difficulty in breathing. Sensory irritation by formaldehyde has been reported for concentrations as low as 0.15 mg/m3 (120 ppb). High concentrations may trigger attacks in people with asthma. There is evidence that some people can develop a sensitivity to formaldehyde. It has also been shown to cause cancer in animals and formaldehyde is classified by IARC as carcinogenic to humans (Group 1).
Guidelines and Standards
The WHO has established an indoor air quality guideline for exposure to formaldehyde of 0.1 mg/m3 (80 ppb) as a 30-minute average. Local guidelines range from 8 ppb to 100 ppb depending on the environment and duration of exposure
Formaldehyde Measurement and Action
Knowing the indoor formaldehyde concentration is the first step towards reducing the exposure below the recommended levels. However, monitoring these low concentrations at and below the limits stipulated in the guidelines for private and public buildings has been a challenge: Traditional precise measurements methods require local sampling and remote analysis in a specialized laboratory instrument. On-line monitors based on traditional electrochemical sensors suffer from their cross-sensitivity to other VOCs, making reliable formaldehyde measurements in the parts-per-billion range difficult.
Formaldehyde levels can be reduced effectively by increasing ventilation with a controlled air exchanger or by opening a window, or by using air treatment devices with specific formaldehyde removal technology.
CMOSens® Technology for Formaldehyde Sensing
The SFA30 is based on an amperometric electrochemical measurement principle enabling lowest cross-sensitivity and an excellent long-term stability. At the working electrode, formaldehyde is decomposed and an electrical current flows between the counter electrode and the working electrode. The current is proportional to the formaldehyde concentration. Thanks to the Sensirion-specific chemistry the sensor is selective to formaldehyde with respect to other VOCs.
