How to get 500,000ppm value of co2 using any of gas sensors

Hi guys,

Help needed.

I am trying to integrate MQ135 and MG811 sensors for detecting CO2. But their sensitivity is only till 10000ppm that is 1% of CO2 . But my requirement is more than 30% of CO2 that is 300,000ppm.

I am struck and not able to understand how to get the desired ppm.

Is it possible to use multiple sensors in series to get high ppm else any other sensor with high ppm or any other method.

Kindly help out with the possible solution.

You need a different sensor or you need to dilute the test sample with a known amount of CO2 free air.

Dilution of the sample in the pipes is not possible since I wanted the exact readings.
Can you tell me which sensor can I use to get such a high ppm value.

It is utterly impossible to obtain "exact readings". If you can't find a sensor with the appropriate range, dilution is your ONLY option.

kirans: Dilution of the sample in the pipes is not possible since I wanted the exact readings. Can you tell me which sensor can I use to get such a high ppm value.

Dilution doesn't mean you can't have exact readings. You just have to be exact about measuring the two amounts of gas.

Hi Kirans, if you want to measure such high concentrations of CO2 (500.000 ppm is 50%), then I can recommend using appropriate CO2-sensors from GSS https://www.gassensing.co.uk/products or at https://www.co2meter.com/collections/co2-sensors because they are respectively producing/distributing 0-60% and even 0-100% NDIR-CO2-sensors which are also much less power consuming than the MQ/MG sensor range.