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How to Measure CO2 with a Low-Cost Sensor and a Raspberry Pi

8 points by joshefin 7y ago

693471 7y ago
You are not going to get an accurate CO2 sensor for $27. You're being misled into buying cheap Chinese crap. An accurate CO2 sensor is much more expensive. I would not trust the readings of the sensor in this blog. It's going to be off by over 100ppm, especially if there's a lack of good airflow. https://www.atlas-scientific.com/product_pages/probes/ezo-co2.html https://www.atlas-scientific.com/product_pages/probes/ezo-co...
- emergie 7y ago
  Oh god, I have never seen a datasheet like this https://www.atlas-scientific.com/_files/_datasheets/_probe/EZO_CO2_Datasheet.pdf https://www.atlas-scientific.com/_files/_datasheets/_probe/E...
  - Isamu 7y ago
    Is that a favorable response? It seems thoughtfully designed. I especially like the warnings in the beginning. Usually I prefer a higher density of information, but this is not too shabby.
    - emergie 7y ago
      Well it has most of the data, but the form is a bit unappealing. For comparision - this is a datasheet of a temperature sensor device: http://pdf.datasheetcatalog.com/datasheet/maxim/DS18B20.pdf http://pdf.datasheetcatalog.com/datasheet/maxim/DS18B20.pdf Electrical characteristics, operation principles, state machines and so on, and it is suitable for printing. EZO-CO2(tm) datasheet looks crazy. page 3 is a big poster warning about submerging of the sensor page 4 is a big poster warning about bright light interference page 5 is a big poster warning about ground loops 1/3 of page 10 is a cartoon picture of a production line.
- joshefin 7y ago
  Senseair is a Swedish company and definitely not "cheap Chinese crap". Do you know about any research that confirms your statements about the accuracy? I believe that some of the more expensive sensors are more accurate, but this cheap one may be a good enough solution in some cases (e.g. indoor air monitoring for DIY projects).
  - 693471 7y ago
    The research has been done by the weed growing community. I don't know any professional growers using sensors outside of the American Scientific as the cheap ones are inaccurate and failure prone.

8 points by joshefin 7y ago

You are not going to get an accurate CO2 sensor for $27. You're being misled into buying cheap Chinese crap. An accurate CO2 sensor is much more expensive. I would not trust the readings of the sensor in this blog. It's going to be off by over 100ppm, especially if there's a lack of good airflow. https://www.atlas-scientific.com/product_pages/probes/ezo-co2.html https://www.atlas-scientific.com/product_pages/probes/ezo-co...

emergie 7y ago
Oh god, I have never seen a datasheet like this https://www.atlas-scientific.com/_files/_datasheets/_probe/EZO_CO2_Datasheet.pdf https://www.atlas-scientific.com/_files/_datasheets/_probe/E...
- Isamu 7y ago
  Is that a favorable response? It seems thoughtfully designed. I especially like the warnings in the beginning. Usually I prefer a higher density of information, but this is not too shabby.
  - emergie 7y ago
    Well it has most of the data, but the form is a bit unappealing. For comparision - this is a datasheet of a temperature sensor device: http://pdf.datasheetcatalog.com/datasheet/maxim/DS18B20.pdf http://pdf.datasheetcatalog.com/datasheet/maxim/DS18B20.pdf Electrical characteristics, operation principles, state machines and so on, and it is suitable for printing. EZO-CO2(tm) datasheet looks crazy. page 3 is a big poster warning about submerging of the sensor page 4 is a big poster warning about bright light interference page 5 is a big poster warning about ground loops 1/3 of page 10 is a cartoon picture of a production line.
joshefin 7y ago
Senseair is a Swedish company and definitely not "cheap Chinese crap". Do you know about any research that confirms your statements about the accuracy? I believe that some of the more expensive sensors are more accurate, but this cheap one may be a good enough solution in some cases (e.g. indoor air monitoring for DIY projects).
- 693471 7y ago
  The research has been done by the weed growing community. I don't know any professional growers using sensors outside of the American Scientific as the cheap ones are inaccurate and failure prone.