The SCD40 from Sensirion is a high quality Photoacoustic based CO2 sensor capable of detecting 0 to 40000ppm with the best accuracy over 400-2000ppm ±（40ppm+5％）. In order to improve accuracy the SCD40 has integrated temperature and humidity sensing built-in. For additional accuracy the SCD40 also accepts ambient pressure readings！
We've written an Arduino library to make reading the CO2, humidity, and temperature very easy. It can be downloaded through the Arduino Library manager：search for 'SparkFun SCD4x' or it can be found in the Documents tab above.
Note：The SCD40 has an automatic self-calibration routine. Sensirion recommends 7 days of continuous readings with at least 1 hour a day of 'fresh air' for self-calibration to complete.
Experimental Product：SparkX products are rapidly produced to bring you the most cutting edge technology as it becomes available. These products are tested but come with no guarantees. Live technical support is not available for SparkX products. Head on over to our forum for support or to ask a question.
