Adafruit SGP30 Air Quality Sensor Breakout - VOC and eCO2

Adafruit SGP30 Air Quality Sensor Breakout - VOC and eCO2 is a fully integrated MOX gas sensor from the sensor experts at Sensirion. The sensor features I2C interfacing and fully calibrated output signals with a typical accuracy of 15% within measured values. The SGP combines multiple metal-oxide sensing elements on one chip to provide more detailed air quality signals. This gas sensor can detect a wide range of Volatile Organic Compounds (VOCs) and H2 and is intended for indoor air quality monitoring. When connected to a microcontroller (running Adafruit's library code) it will return a Total Volatile Organic Compound (TVOC) reading and an equivalent carbon dioxide reading (eCO2) over I2C.

The SGP30 has a "standard" hot-plate MOX sensor, and a small microcontroller that controls power to the plate, reads the analog voltage, tracks the baseline calibration, calculates TVOC and eCO2 values, and provides an I2C interface to read from. Unlike the CCS811, this sensor does not require I2C clock stretching. This part will measure eCO2 (equivalent calculated carbon-dioxide) concentration within a range of 0 to 60,000 parts per million (ppm), and TVOC (Total Volatile Organic Compound) concentration within a range of 0 to 60,000 parts per billion (ppb).

This sensor has variability and to get precise measurements needs to be calibrated against known sources. For general environmental sensors, it will give a good idea of trends and comparison. The SGP30 does have built in calibration capabilities, note that eCO2 is calculated based on H2 concentration, it is not a 'true' CO2 sensor for laboratory use. Another nice element to this sensor is the ability to set humidity compensation for better accuracy. An external humidity sensor is required and then the RH% is written over I2C to the sensor, so it can better calculate the TVOC/eCO2 values. The sensor is pick-and-placed on a PCB with a 1.8V regulator and some level shifting so it can be easily used with a 3.3V or 5V microcontroller.