The MIKROE-2896 air quality 4 Click board™ from MikroElektronika is an advanced air quality sensing device that combines multiple metal oxide sensing elements on a chip to provide detailed information of the air quality parameters. This click can output total volatile organic compounds (TVOC) value readings as well as the CO₂ equivalent concentration readings in an indoor environment. Besides these compensated attributes, the click can also output raw values of H₂ and ethanol in the air that can be used to calculate gas concentrations relative to a reference concentration. The sensor used on air quality 4 click is actually a complete system of sensors on a chip, featuring I²C interface, a temperature controlled micro hotplate, and two compensated and processed indoor air quality signals. It is produced using the proprietary CMOSens® technology, which provides very detailed information and robustness against air contamination.

The sensor IC used on air quality 4 click is the SGP30 from Sensirion, a multi-pixel gas sensor for indoor applications. This sensor is a system of several metal oxide sensing elements on a chip (pixels) used to measure and process readings of various gasses in the air and output them in a form of two complementary air quality readings - (TVOC) (ppb) and CO₂ equivalent signal (ppm).

The traditional metal oxide (MOX) sensors suffer from sensitivity and responsiveness degradation after being exposed to siloxanes over time. Siloxanes are specific compounds commonly found in the air that negatively affect the MOX sensors. To overcome this problem, the SGP30 sensors are made by utilizing the advanced MOXSens® technology, which provides these sensors with the unmatched robustness against siloxanes contamination. This results in unprecedented long-term stability and accuracy. The SGP30 uses a dynamic baseline compensation algorithm and calibration parameters to provide accurate readings of TVOC and CO₂eq properties. These baseline values of the compensation algorithm can be stored externally and read back into the device with the appropriate I²C commands and can be used in an event of power down or restart. For the first 15 seconds after the I²C initialization command, the sensor is in an initialization phase of collecting sensor measurements and baseline compensation data, and will return fixed values of 400 ppm CO₂eq and 0 ppb TVOC when the measurement command is attempted. These attributes make air quality 4 click a perfect solution for various air conditioning systems, ventilation systems, and other IoT applications where accurate, detailed, and reliable air quality readings are required.

Video - Air Quality Click / Advanced Air Quality Sensing Device