BEIJING - Beijing's environment authority on Saturday launched the much-anticipated PM2.5 measure of air quality, fulfilling its promise of publishing the data ahead of the Spring Festival holiday, which starts on Sunday.

The Beijing Environment Protection Monitoring Center said its monitoring station at the city's second ring road had detected 0.003 micrograms per cubic meter, suggesting the air quality is good.

The PM2.5 gauge is considered stricter than Beijing's previous standard of PM10, as it monitors "fine" particles 2.5 microns or less in diameter.

A fierce online public debate on PM2.5 and PM10 began at the end of 2011 when it came to light that air-quality monitoring results released by Beijing's weather forecast station and the US Embassy in Beijing often differed.

On Sunday, the embassy's air-quality rating also suggested the air is "good."