Gas sensor installation

Hello,

I’m going to use the following sensors to monitor some exhagases from one of my project.
These are the sensors:

CO2:
https://www.seeedstudio.com/Grove-VOC-and-eCO2-Gas-Sensor-SGP3-p-3071.html

NH3:
https://www.seeedstudio.com/Grove-Multichannel-Gas-Sensor-p-2502.html

O2:
https://store.arduino.cc/grove-gas-sensor-o2

Since one of my requirements it is to measure those gasses in a 10DN (3/8) pipe,
pratically they will not fit in. There is a better way to measure those gasses trogh anoter type of casing with those sensor? Like a pipe ready casing?

In alternative I’ve figured to mount a terminal box to store the gasses and measure them there but im not sure if the measurment will be corret cause the gas dispersion in the box is not equal. Am i right?Any advice?

Thanks-

c000150_featured.jpg

Before you build a complex enclosure, test each sensor under a range of known conditions to make sure that it will perform satisfactorily.

Many cheap gas sensors discriminate poorly, require frequent calibration and are unreliable.

add 2 tee fittings.
connect an air tight box to those fittings and put all your sensors inside.
as the air moves through the pipe, some will enter on of the fittings, pass through the box, then exit out the other fitting.

another way might be to add 3 Tee fittings and have the sensor in the new pipe. just really close to the main line.

If you understand Partial Pressures of Gasses, you will understand that the gas levels will be representative at the sensors.

if the process is not able to be shut down easily, the first way could have valves fitted to isolate the box for any work.

google duct smoke detectors to see how this is done in the commercial world.