Hi.
I´m also looking for a cheap co2 sensor, but for outdoor measurements, it should have high range (=>10000ppm) , but the accuracy is not a requirement, i´m looking for in the thousands range.
Giving an example:
-A street has 2 street sewage drain, i want to check if any has a high volume of co2..but i´m not interested to know if sewage drain 1 has more 123ppm than sewage drain 2..i´m looking for abnormal values, like, sewage drain 1 has 1000ppm, and sewage drain 2 has 4000ppm.
Since i never worked with similar sensors, i dont know if is even possible to do measurements in the outdoor (not placing the sensor inside the sewage drain), in a relative fast way (ie: not leaving the sensor for hours in the location).