PPM of CO in air (using an MQ-9 sensor) [closed]

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I need to find the PPM of CO (carbon monoxide) in air using the MQ-9 sensor with an Arduino.

Using the analog input from the sensor, how can I calculate the CO PPM?arduinosensorShareCiteEditFollowFlagedited 15 hours agoocrdu3,88399 gold badges1717 silver badges2727 bronze badgesasked 15 hours agouser1489621611 New contributor

EditFollowFlagedited 15 hours agoocrdu3,88399 gold badges1717 silver badges2727 bronze badgesasked 15 hours agouser1489621611 New contributor

• 5Read the fabulous data sheet. – Andy aka 15 hours ago
• 1Datasheet seems pretty comprehensive. It’s a low-grade sensor and will require calibration and temperature compensation to get any semblance of accuracy. Calibration would typically use a bottle of calibration gas purchased as such from a supplier. – Spehro Pefhany 14 hours ago
• I once played with MQ-9, but I did not use any calibrated gas standard to do the calibration. I just used a candle and “some air”. 🙂 Ref: How Can Rpi3B+ read MQ9 Gas Sensor? – RpiSE Q&A, Asked 2019oct30, Viewed 1k times. (1) raspberrypi.stackexchange.com/questions/105116/… (Q&A) (2) chat.stackexchange.com/rooms/100573/… (Chat). – tlfong01 14 hours ago    
• 2@tlfong01 cool! But that gives you a “is there more than normal?” not a “what’s the concentration?” – Marcus Müller 13 hours ago
• 1@Marcus Müller, Ha yes, but I am just a friendly hobbyist, and my calibration is just “yes” and “no”, or “1 candle light” or “0 candle light”. But giving me standard calibrated CO gas bottles, my ADC can calibrate to 24-bit resolution, or higher accuracy than 1ppm. 🙂 – tlfong01 12 hours ago   
• 1Hum … you can use also for simplicity this one (or some equivalent) for “calibrating” … adafruit.com/product/3199 – Antonio51 12 hours ago
• Yes, MiCS5524 is better. I am happy to update my old RpiSE Q&A MQ-9 answer here, with MiCS5524, and how to convert ppm to 16/24-bit ADC results to ppm, if anybody is interested. – tlfong01 48 mins ago    Delete

• 5Read the fabulous data sheet. – Andy aka 15 hours ago
• 1Datasheet seems pretty comprehensive. It’s a low-grade sensor and will require calibration and temperature compensation to get any semblance of accuracy. Calibration would typically use a bottle of calibration gas purchased as such from a supplier. – Spehro Pefhany 14 hours ago
• I once played with MQ-9, but I did not use any calibrated gas standard to do the calibration. I just used a candle and “some air”. 🙂 Ref: How Can Rpi3B+ read MQ9 Gas Sensor? – RpiSE Q&A, Asked 2019oct30, Viewed 1k times. (1) raspberrypi.stackexchange.com/questions/105116/… (Q&A) (2) chat.stackexchange.com/rooms/100573/… (Chat). – tlfong01 14 hours ago    
• 2@tlfong01 cool! But that gives you a “is there more than normal?” not a “what’s the concentration?” – Marcus Müller 12 hours ago
• 1@Marcus Müller, Ha yes, but I am just a friendly hobbyist, and my calibration is just “yes” and “no”, or “1 candle light” or “0 candle light”. But giving me standard calibrated CO gas bottles, my ADC can calibrate to 24-bit resolution, or higher accuracy than 1ppm. 🙂 – tlfong01 12 hours ago   
• 1Hum … you can use also for simplicity this one (or some equivalent) for “calibrating” … adafruit.com/product/3199 – Antonio51 12 hours ago
• Yes, MiCS5524 is better. I am happy to update my old RpiSE Q&A MQ-9 answer here, with MiCS5524, and how to convert ppm to 16/24-bit ADC results to ppm, if anybody is interested. – tlfong01 44 mins ago    

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