The Accuracy of our CO2 Sensors

NDIR CO2 SensorA recent scientific study has found that the CO2 sensors found in many of our detectors are highly accurate.

The CO2 sensor inside of our CO2 detectors is based on Non-Dispersive Infra-Red (NDIR) technology. NDIR is a low cost approach to measuring carbon dioxide for indoor air quality (IAQ) and HVAC applications. Since it is low cost, some users have questions the accuracy of the sensors.

Undoubtedly, there are some NDIR CO2 sensors that are poor quality. However scientists in Sweden recently compared the CO2 sensors in our detectors against a standard and found them to be highly accurate.

Our CO2 sensors cost in the order of hundreds of dollars, yet the standard the Swedish scientists compared them to is a high precision, scientific laboratory instrument that costs in the hundreds of thousands of dollars.

The proof can be easily seen in the following graph. The x-axis is our CO2 sensor and the y-axis is the expensive laboratory instrument standard. The line through the graph is the 1:1 line – meaning that if the data (circles in the graph) fall on this line then there is an exact relationship between the two different measurement techniques.

CO2 Sensor Comparison

A comparison of an NDIR CO2 sensor versus an expensive, laboratory CO2 instrument. Source: Bastviken et al 2015, Figure 2.

 

As can be seen in the above graph, the data fall exactly on the 1:1 line. Therefore, you can have high confidence that the CO2 measurements you are recording with many of our sensors matches exactly with some of the most expensive scientific measurements available.

 

Reference

Bastviken et al 2015. Biogeosciences, 12, 3849 – 3859