DFROBOTGravity: Analog CO2 Gas Sensor

This is an incredibly accurate and powerful sensor. They've even gone so far as to include a heating coil to make sure measurements always occur at the same temperature. The chip is well designed and they've definitely put a lot of care into making a quality board.I was a bit concerned by reading the other reviews, but after doing a small amount of calibration work (read the Questions section to find out how to calibrate - it's pretty simple), I was able to get this sensor working very well.Because of the heating coil, the sensor can get quite hot, but it's worth it to get more accurate readings. Overall, I would highly recommend this sensor, especially since it's so cheap!

I want to give this item three stars because the PCB and components are high quality and care was obviously given when designing this unit. HOWEVER....read on for my rationale behind this two star flop.Poor available documentation and datasheet available for this mg-811 breakout. Datasheet displays a completely different sensitivity curve than is actually detected by the sensor.Placed unit in 3000ppm co2 calibrated gloved box and it continually floats to lower voltages over two weeks time despite no additional co2 being introduced to environment. Sensor fluctuates despite consistent ambient temp/humidity and adequate warming unit temperature.Supplied code is so inaccurate it is unusable. Factory uncalibrated and frustratingly floats through baseline calibration algorithms that work for other co2/gas sensors. My NDIR sensors are far more reliable, calibrate on algorithm properly and only cost about 10 dollars more...look around and you'll find them. Good luck to all those others seeking accurate environmental co2 readings.

Must include calibration kit, otherwise you don’t really know what are the meaning of the readings.

The sensor stopped working after a few hours. I cannot even return it now as it is past the return date. I would not buy this again.

having difficulty finding a sketch that works to operate this sensor on Arduino for testing...