Comde-Derenda Wuxi has been tasked to carry out comparison measurements of PM1 concentration for the “Blue Sky” campaign of the China National Environmental Monitoring Center (CNEMC). By means of those measurements, basic data for the development of PM1 standards and limit values is retrieved. At the same time, data concerning the comparability of measurement results with regard to geographical characteristics and the application of different measurement methods is gathered. Particularly, comparative studies between manual and automatic measurement of fine particulate matter are needed. Results are taken into consideration for technical standards and directives.
The first period of pilot PM1 comparison tests took place from October 2017 to January 2019. According to the current directives HJ618 and HJ656, Comde-Derenda has installed measurement stations in six cities (Beijing, Shanghai, Guangzhou, Wuhan, Chongqing and Lanzhou). At each station, measurements have been carried out for each 30 days in all four seasons. As measurement device for manual fine particulate matter measurement, the Low Volume Sampler LVS of Comde-Derenda GmbH has been used. The real-time monitoring devices within the comparison worked with the beta ray attenuation method as well as TEOM method (Tapered Element Oscillating Microscale) and scattered light method (nephelometry).
Comde-Derenda Wuxi is responsible for carrying out the standard analytical method (manual gravimetric measurement) as a benchmark for various real-time measurement methods. Since approximately one year, the PM1 comparison measurement is completed successfully. The LVS of Comde-Derenda GmbH is characterized by its excellent consistency and comparability of measurement values. The average deviation for all six measurement stations was maximum 2 μg/m³.
For the monitoring of fine particulate matter within ambient air by gravimetric analysis, Comde-Derenda GmbH provides excellent quality, efficient service and long-term experience. Therefore, the main measurement station uses only the LVS as manual reference device for the PM1 pilot comparison measurement. Additionally, the AWS of Comde-Derenda GmbH serves as automatic weighing system for the gravimetric analysis of PM1 sampling filters.