To whom may concern,
We have been checking the air quality index since last year, however we found the data has such a big difference between your website and another official one which is stated on yours as well. I am wondering which one can provide more accurate data, as it will affect the decision for outdoor or indoor. Please help me with this issue. Thank you!
Check the answer from this post: http://aqicn.org/faq/2015-03-20/a-comparison-of-worldwide-air-quality-scales-part-1/