High performance in a small size – disruptive CO2 sensor based on photoacoustic spectroscopy (PAS)
Use Infineon’s XENSIVTM PAS CO2 sensor to track the environment you are in – for improved health, productivity and overall well-being.
Increasingly efficient building insulation can help to mitigate the effects of climate change, but heavily-insulated buildings are not always good for human health. Poor ventilation can result in lower oxygen levels and a build-up of carbon dioxide (CO2). Even moderate levels of CO2 can have a negative impact on health and productivity. Already at 1000ppm, people begin to experience drowsiness and have difficulty concentrating. Consequently, there is a growing demand for smart indoor air quality sensors that can “smell” rising levels of CO2 and either alert the user or trigger a system response.
Measure what matters with our XENSIV™ PAS CO2 sensor
With the current pandemic, awareness of indoor air quality is rising, making accurate, affordable monitoring solutions like the XENSIV™ PAS CO2 sensor more important than ever. It has been shown that a correlation exists between the concentration of CO2 and aerosols, one of the transmission pathways of COVID-19. Therefore, if we can reliably measure the CO2 level in an indoor space, we can actively manage the risk of virus transmission.
Widespread adoption of CO2 sensors has so far been hampered by size, performance and cost constraints. Infineon’s XENSIV™ PAS CO2 sensor leverages photoacoustic spectroscopy (PAS) technology to provide an exceptionally small, real CO2 sensor, overcoming the challenges of existing CO2 sensor solutions. Its unprecedentedly small form factor in SMD (Surface Mounted Device) package allows for smooth high-volume assembly and easy system integration.
Accurate, real-time CO2 measurement thanks to superior MEMS technology
Along with size and cost advantages, the sensor delivers superior accuracy, providing a direct readout of the real CO2 level, not simply a correlation. Infineon’s leading position in MEMS technology is the foundation for this unique and accurate CO2 detection approach. Reliable CO2 measurement enables smart monitoring of indoor air quality, allowing users to take control of their environmental conditions and experience improvements in health, productivity and overall well-being.
XENSIVTM PAS CO2 sensor will be available via distributors mid of 2021.
Disruptive environmental sensor technology from Infineon
The XENSIV™ PAS CO2 integrates on the PCB the photoacoustic (PAS) transducer, including a detector, infrared source and optical filter; a microcontroller for signal processing and algorithms; and a MOSFET chip to drive the infrared source. The integrated microcontroller runs ppm calculations as well as advanced compensation and configuration algorithms.
The sensor uses a MEMS acoustic detector. The exceptional sensitivity of this acoustic detector coupled with the integrated PCB design reduce space requirements by more than 75 percent compared to commercially available real CO2 sensors. Therefore, the XENSIVTM PAS CO2 sensor outperforms state-of-the-art NDIR sensors in terms of size and cost, without compromising on performance.
The Photoacoustic Spectroscopy (PAS) Principle
The PAS principle works as follows. Pulses of light from an infrared source pass through an optical filter tuned specifically to the CO2 absorption wavelength (λ= 4.2 µm). The CO2 molecules inside the measurement chamber absorb the filtered light, causing the molecules to shake and generate a pressure wave with each pulse. This is called the photoacoustic effect. The highly sensitive MEMS acoustic detector detects the pressure change generated by CO2 molecules within the sensor cavity, and the microcontroller converts the output into a CO2 concentration reading. In order to achieve a ppm reading as accurate as possible, the acoustic detector is optimized for low frequency operation, and the absorption chamber is acoustically isolated from external noise.
Improving air quality in smart homes and automated buildings
The new sensor is ideal for high-volume, cost-sensitive smart home and building automation applications such as demand-controlled ventilation systems, air purifiers, thermostats, weather stations and personal assistants. By integrating CO2 measurement into these systems, significant amounts of energy can be saved and indoor air quality can be greatly improved, leading to a lower energy bill and a healthier indoor environment. Infineon is making a valuable contribution to enable everyone to track their environment in a smart, easy-to-use and affordable way – for a better and healthier life!