Hello Ma'am/Sir, I am new with Arduino. My question is, is it possible that Arduino can handle with 3 or more gas sensors in one Breadboard ? And if that so, is there a code that can show separate all the collected gases by individual sensors ? for example.
MQ-7 MQ-?
(Carbon Monoxide) (Carbon Dioxide) etc.
222pm 20ppm
Thank you for Answering 
Yes.
But why not continuing your previous thread?
Its just an example sir, but it is what i want to do with our thesis study. Hope you can help us Sir
I suspect you will have two problems:
The sensors are not factory calibrated to produce 'ppm' values. To get 'ppm' values you will need to calibrate them and for that you will need known concentrations of the gasses being measured.
The sensor are usually sensitive to more than one gas. Look at the sensitivity curves in the product documentation. To get concentration for an individual gas you will have to calculate based on the relative sensitivity of multiple sensors. For example, if the CO2 and CO sensors indicate gas it could be CO2 and the CO sensor is also sensitive to CO2, or it could be CO and the CO2 sensor is also sensitive to CO, or it could be a third gas like Methane and both sensors are also sensitive to Methane.
Good Luck!
You need to look to the technology behind these sensors to see how they work , they are not gas specific
You might need a gas chromatograph or dedecate IR analysers. These are all expensive, which gives a clue !
If you’ve specific gas mixes , or ratios you could look at thermal conductivity or resonant cavities ( to get speed of sound) or other physical properties and infer gas concentrations from that . Not easy ( there are, cough, some patents on this )
Do not double post.