Air quality

This is very area ranging from level of O2 CO2 to level of poisson gasses like CO and other gasses.
The prices for a sensor range from maybe 30 dkk to several 1000 KK

MQ sensors

In the bottom is link to a unified library which handles all the mq sensors shown her

Disclaimer : I have not tested it - but it looks nice.

Arduinotech has a long list of mq sensors here

Robocraze.com has more information here

Purpose/Type of gasses

Many of the sensors has a sensitivity graph. Please note that y-axis i logaritmic

• MQ - 2 Methane, Butane, LPG, smoke

  • https://www.sparkfun.com/smoke-sensor-mq-2.html

  • https://circuitdigest.com/microcontroller-projects/interfacing-mq2-gas-sensor-with-arduino

  • https://randomnerdtutorials.com/guide-for-mq-2-gas-smoke-sensor-with-arduino/

• MQ - 3 Alcohol, Ethanol, smoke

  • https://www.sparkfun.com/alcohol-gas-sensor-mq-3.html

  • https://circuitdigest.com/microcontroller-projects/interfacing-mq3-alcohol-sensor-with-arduino

• MQ - 4 Methane, CNG Gas (dyr)

  • https://www.sparkfun.com/methane-cng-gas-sensor-mq-4.html

  • https://www.makerguides.com/using-the-mq4-methane-gas-sensor-with-arduino-made-easy/

• MQ - 5 Natural gas, LPG

  • https://circuitdigest.com/microcontroller-projects/interfacing-mq5-gas-sensor-with-arduino

• MQ - 6 LPG, butane gas

  • https://www.sparkfun.com/lpg-gas-sensor-mq-6.html

• MQ - 7 Carbon Monoxide

  • https://www.sparkfun.com/carbon-monoxide-sensor-mq-7.html

  • https://www.instructables.com/Arduino-CO-Monitor-Using-MQ-7-Sensor/

• MQ - 8 Hydrogen Gas

  • https://www.sparkfun.com/hydrogen-gas-sensor-mq-8.html

• MQ - 9 Carbon Monoxide, flammable gasses

  • https://www.sparkfun.com/dual-gas-co-and-ch4-detection-sensor-mq-9b.html vrs 9b

  • https://www.instructables.com/How-to-Calibrate-Use-MQ9-Gas-Sensor-W-Arduino/

• MQ - 131 Ozone

• MQ - 135 Air Quality (CO, Ammonia, Benzene, Alcohol, smoke)

  • https://www.instructables.com/Easy-Air-Quality-Report-With-NodeMCUMQ135Cayenne/

  • https://circuitdigest.com/microcontroller-projects/interfacing-mq135-gas-sensor-with-arduino-to-measure-co2-levels-in-ppm

• MQ - 136 Hydrogen Sulfide gas

  • https://www.sparkfun.com/hydrogen-sulfide-gas-sensor-mq-136.html

• MQ - 137 Ammonia

  • https://www.sparkfun.com/ammonia-gas-sensor-mq-137.html

Other

A nice project about air quality SPG40 sensor

• https://www.instructables.com/Room-Air-Quality-Monitor/

Other from Sparkfun:

• https://www.sparkfun.com/sparkfun-environmental-sensor-bme688-qwiic.html

• https://www.sparkfun.com/sparkfun-environmental-sensor-bme688-qwiic.html

• https://www.sparkfun.com/sparkfun-environmental-sensor-breakout-bme680-qwiic.html

• https://www.sparkfun.com/sparkfun-ambient-light-sensor-veml7700-qwiic.html

• https://www.sparkfun.com/gas-sensor-module-zmod4450.html

A unified sensor library - for MQ2, MQ3, MQ4, MQ5, MQ6, MQ7, MQ8, MQ9, MQ131, MQ135, MQ303A, MQ309A.

• an unified library for all the sensors - I have NOT tried it

• https://github.com/miguel5612/MQSensorsLib the library

SOME THING TO NOTE

• energy consumption

• time to warm up when switched on until first measurement is valid

• Qality of data

  • accuracy

  • range: PPM: parts pr million

Always under construction

THE BEER-WARE LICENSE (Revision v 42) jensd@jensd.dk wrote this file.
As long as you retain this notice you can do whatever you want with this stuff on these pages.
If we meet some day, and you think this stuff is worth it, you can buy me a beer in return :-)
(C) Jens Dalsgaard Nielsen
credit for license this goes to phk@FreeBSD.ORG