Soldered MQ7 - carbon monoxide CO sensor with Qwiic interface

Module with hydrogen sulphide sensor made in MEMS technology. It allows gas detection in the range of 0.5 to 50 ppm and has an analog output. DFRobot SEN0568

Module with ammonia sensor made in MEMS technology. It allows gas detection in the range of 1 to 300 ppm and has an analog output. DFRobot SEN0567

Module with a VOC sensor (volatile organic compounds) made in MEMS technology. It allows gas detection in the range of 5 to 500 ppm and has an analog output. DFRobot SEN0566

Methane sensor module made in MEMS technology. It allows gas detection in the range of 1 to 10000 ppm and has an analog output. DFRobot SEN0565

Module with a smoke concentration sensor made in MEMS technology. It allows gas detection in the range of 10 to 1000 ppm and has an analog output. DFRobot SEN0570

Module with a formaldehyde sensor made in MEMS technology. It allows gas detection in the range of 0 to 3 ppm and has an analog output. DFRobot SEN0563

Module with ethanol sensor made in MEMS technology. It allows gas detection in the range of 1 to 500 ppm and has an analog output. DFRobot SEN0569

Module with nitrogen dioxide sensor made in MEMS technology. It allows gas detection in the range of 0.1 to 10 ppm and has an analog output. DFRobot SEN0574

Formaldehyde sensor (HCHO) dedicated to measuring ambient air quality. It is used to detect whether the surrounding environment exceeds a set concentration threshold. It is powered by a voltage of 5 V to 24 V and has an output in the form of a two-state digital signal. DFRobot SEN0595

Module with a CO2 sensor based on the XENSIV PAS CO2 system from Infineon. It enables precise measurement of CO2 concentration in ppm via I2C, UART and PWM interfaces. SparkFun SEN-2295

Digital sensor dedicated to measuring carbon dioxide (CO2), air temperature and relative humidity. High performance, fast response and excellent stability make it an ideal solution for a variety of applications such as greenhouses, cities, poultry farms and transport stations. Seeed Studio 101991029

A digital gas and air quality sensor that measures eCO2, TVOC, and the AQI air quality index. The device utilizes metal-oxide technology with four sensor sections and an embedded microcontroller, simplifying operation and integration with Arduino, Raspberry Pi, and CircuitPython platforms. The sensor supports I2C and SPI interfaces, as well as temperature and humidity compensation using an external sensor. The compact design and STEMMA QT/Qwiic standard allow for easy integration into projects. Adafruit 6431

A compact 3-in-1 module that simultaneously measures CO₂ concentration, temperature, and humidity. With 2.4 GHz Wi-Fi connectivity and MQTT and REST API support, it easily integrates with IoT systems and cloud platforms. It offers local data storage, a built-in web server, and an RGB indicator for air quality. Numato Lab NLSENZA002

An environmental sensor based on the BME688 sensor, enabling simultaneous measurement of temperature, humidity, atmospheric pressure, and air quality. The device detects volatile organic compounds and calculates CO₂ equivalent and IAQ, allowing for accurate monitoring of indoor conditions. Communication via an I2C interface ensures easy integration with microcontrollers and platforms such as Arduino and UIFlow. M5Stack U169

SGP41 gas sensor module for VOC and NOx measurement with I2C interface and STEMMA QT/Qwiic connectors, equipped with dual MOX sensing elements. Adafruit 6455