Environmental Sensors

Environmental conditions have a major impact on our well-being, comfort, and productivity. Sensirion’s sensor solutions provide detailed and reliable data on key environmental parameters such as humidity, temperature, volatile organic compounds (VOCs), formaldehyde, particulate matter (PM2.5), and CO2. Environmental Sensing opens up new possibilities to create smarter devices that improve our comfort and well-being as well as increase energy efficiency in a wide variety of applications.
Product Highlights
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.
The SEK-SCD41 evaluation kit represents the perfect tool kit for effective SCD4x sensor evaluation and efficient prototyping. The evaluation kit contains a SCD41 CO2 sensor mounted on a development board with a JST connector and through-hole pins. The included adapter cable (JST-Ethernet) connects to Sensirion’s SEK-SensorBridge for easy evaluation of the sensor via the SEK-ControlCenter viewer software. Finally, the kit contains a 4-pin jumper wire cable that enables fast prototyping, e.g. through integration into existing platforms (like Arduino, Raspberry Pi and so on).
Videos
Key Environmental Parameters

Carbon Dioxide
CO2 is part of the human metabolism. It is produced when, for example, carbohydrates are metabolized to generate energy. The produced CO2 is then transported out of the body by respiration. The CO2 concentration in the inhaled air is decisive for the metabolism. Depending on the level of the concentration in the air breathed in, various symptoms can occur that affect daily life and health. High CO2 concentrations in the air we breathe lead to concentration problems and fatigue. The performance potential of people in the room decreases constantly the higher the amount of CO2 in the air gets. Furthermore, CO2 concentrations relate to the potential of virus infections.
The level of CO2 in the air can be thought of as a "traffic light" system: Green is between 400–1'000 ppm; yellow is between 1'000–1'600 ppm and is where 80% of people are satisfied with perceived air quality; red is ≥1'600 ppm and is where there are detectable negative impacts on human health and well-being. At this level, the air quality is considered poor and the risk of viral transmission is increased.

Humidity and Temperature
Do you find it hard to breathe in your home some days? Are you more prone to headaches and asthma attacks during the summer months? You’re not allergic to heat - but you may have serious humidity problems in your home or office. When we talk about indoor air quality, humidity is one of the main things we’re referring to. Too high or too low humidity levels in closed spaces can lead to various issues. For example, bacteria and viruses that cause respiratory infections thrive in extremely high and extremely low humidity. Mold spores, dust mites and other allergens survive best in high humidity environments. Furthermore, higher humidity can increase the levels of noxious chemicals in the air, which may include ozone and formaldehyde.
40-60 % relative humidity is an optimal level for the immune system and our respiratory system. It reduces the spread of seasonal respiratory diseases and increases well-being. Scientists are therefore calling on the WHO (World Health Organization) to revise the global guidelines for indoor air quality with the petition 40to60RH. Click here to learn more about it.

Volatile Organic Compounds (VOCs)
VOCs originate from a number of different possible sources, like building materials, tobacco smoke, people and their activities, and indoor chemical reactions. Exceptionally high VOC levels are typically found in new buildings or after renovation. Further, when using products that contain VOCs, such as air fresheners or cleaning agents, people expose themselves and others to high pollutant levels that can persist long after the activity has finished. A number of systematic human exposure studies have shown various adverse health
effects caused by exposure to elevated VOC levels. Among the effects reported by participants are dryness and irritation of the eye, the nose and the throat, headaches, and dizziness.
Sensirion’s powerful VOC Algorithm analyzes VOC events detected by the SGP40 sensor and maps them to a VOC Index. This VOC Index provides a practical quantification of VOC events relative to each individual sensor’s typical indoor environment. In this way, it behaves similarly to the human nose, which is highly susceptible to changes in odor, but it also detects VOC events that are not perceived by humans. The VOC Index indicates to what extent the indoor air quality has deteriorated or improved compared to the sensor’s typical VOC environment. Learn more about the VOC index at www.sensirion.com/sgp40.

Particulate Matter (PM2.5)
Particulate Matter (PM) is a complex mixture of solids and aerosols composed of small droplets of liquid, dry solid fragments, and solid cores with liquid coatings. Particles are defined by their diameter for air quality regulatory purposes. Those with a diameter of 10 microns or less (PM10) are inhalable into the lungs and can induce adverse health effects. A number of adverse health impacts have been associated with exposure to PM2.5. Short-term exposures (up to 24-hours duration) have been associated with premature mortality, increased hospital admissions for heart or lung causes, acute and chronic bronchitis, asthma attacks, emergency room visits, respiratory symptoms, and restricted activity days.
Indoor PM levels are dependent on several factors including outdoor levels, infiltration, types of ventilation and filtration systems used, indoor sources, and personal activities of occupants. In homes without smoking or other strong particle sources, indoor PM would be expected to be the same as, or lower than, outdoor levels. To know what the limits of PM exposure are, please consider official air quality standards. The US Environmental Protection Agency defines the AQI levels as follows: With regard to primary (health-based) standards for fine particles (generally referring to particles less than or equal to 2.5 micrometers (mm) in diameter, PM2.5), the EPA is revising the annual PM2.5 standard by lowering the level to 12.0 micrograms per cubic meter (mg/m3) so as to provide increased protection against health effects associated with long- and short-term exposures (including premature mortality, increased hospital admissions and emergency department visits, and development of chronic respiratory disease), and to retain the 24-hour PM2.5 standard at a level of 35 mg/m3.

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.
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
With Our Environmental Sensing Solutions, We Improve…
Health

Your health is your greatest asset. In order to enable more people to live longer, healthier and happier lives, Sensirion has developed sensor solutions to improve medical devices and smart home applications such as air purifiers and air cleaners.
Quality Of Life

Deep down, everyone is looking to increase their quality of life, and Sensirion’s unique, intelligent sensor solutions do just that. As the leading international manufacturer of environmental sensor solutions, we offer our clients sensor solutions for increased convenience and security.
Energy Efficiency

With efficient systems, we have the chance to significantly improve the global energy balance and make a major contribution to environmental protection. Through energy-efficient applications, we can counteract the constantly growing energy consumption around the world and at the same time reduce harmful emissions. That’s why we offer our clients in a wide variety of industries sensor solutions for sustainable and efficient energy management.
Hot Topics

Reduce the risk of virus infection in classrooms
Ventilate indoor spaces regularly and thoroughly - this is recommended by the Federal Environment Agency to reduce the risk of Sars CoV-2 infection. This announcement is particularly relevant in view of the fact that the school has started again at full class size. For this reason, the supply of fresh air in the classrooms should also be as high as possible, regardless of other protective measures such as keeping minimum distances or wearing a mouth-and-nose cover. After all, droplets and tiny aerosol particles should play a decisive role in the transmission of Sars-CoV-2. Especially the aerosol particles that are produced when breathing, coughing, speaking and sneezing can float in the air for hours or days, according to current knowledge. Consistent ventilation can significantly reduce the risk of infection, but cannot provide 100% protection.
Petition "40to60RH"

It has been proven that indoor humidity plays an important role in preventing virus transmission and improving the response of the immune system. Extensive research shows that a relative humidity (RH) between 40% and 60% is optimal to minimise the spread of viruses such as influenza. Scientists are therefore calling on the WHO to revise the global guidelines for indoor air quality.
The importance of indoor humitidy is crucial to us. As market leader in humidity sensing it is important to us to support petition 40to60RH. Improving people's health is part of our mission and therefore we encourage everyone to support this petition to gain the attention of the World Health Organization.
Support the petition and learn more about it: www.40to60rh.com
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Test Our Environmental Sensors with Sensirion's Evaluation Kit
With plug-and-play hardware, user-friendly viewer software and compatibility with all environmental sensors, SEK-Environmental Sensing makes evaluation easier and faster than ever before. This allows our customers to focus on developing innovative sensor applications.

Complete Solutions Provider
With more than 15 years’ experience in the development and supply of environmental sensor solutions, we lead the field in sensor technology innovation. We provide the sensor hardware and support our customers during the design-in, the development of sophisticated algorithms and the industrialization all the way to mass production. In addition to providing unparalleled performance, we also focus on key characteristics such as size, ultra-low power consumption, fully calibrated digital output and compatible supply voltages.

Innovation Pioneer
Thanks to our patented CMOSens® Technology, Sensirion was the first company to offer an automotive-grade, digital humidity sensor with a calibrated and linearized signal output. As an innovation-driven company, we did not stop with state-of-the-art humidity sensors, but have continued to develop other sensor types, such as mass flow meters and controllers for gases, differential pressure sensors and liquid flow sensors. We are always keen to find new sensor solutions for demanding applications, which is why our environmental sensor solutions portfolio constantly looks to the future.