SenseAir's K30 carbon dioxide sensor beat a similar-specified GE sensor as well as several other brands in a head-to-head calibration test.
Researchers at the University of Maryland's Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center were testing carbon dioxide sensors at part of a long-term CO2 monitoring project. To verify the accuracy of their test instruments, the researchers calibrated a SenseAir K30 CO2 sensor and a similarly rated GE CO2 sensor. For verification, they also used a pSense handheld unit by CO2Meter.com, and a Picarro Cavity Ring-Down Spectroscopy (CRDS) Analyzer capable of measuring CO2 with parts-per-billion accuracy.
The image shows the calibration graphs for the Picarro, the pSense, and the K30 CO2 sensor in white, with the GE sensor in green. Not only did the GE sensor show below normal CO2 readings in fresh air, but after being tested with CO2 (spike at red arrow), it did not recover quickly.
According to Professor Ning Zeng, "I attached some cross-calibration (data logs) we did with K30, a GE sensor, and pSense handheld compared to the Picarro analyzer on loan to us. As you can see, K30 and pSense both show similar changes as the Picarro."
This calibration test mirrors the results of a 2012 article "Comparison of the Characteristics of Small Commercial NDIR CO2 Sensor Models and Development of a Portable CO2 Measurement Device" in the MDPI Open Access Journals Platform. The article compared the SenseAir with other sensors, and determined the SenseAir K30 was more accurate than the rest when properly calibrated.