This report provides information of quality assurance for PM2.5 sampling activities from November 26, 2020 through Novembeer 25, 2022. The mission of the project comprises implementation of inspection, performance audit, and collocated comparison for field sampling and laboratory analyzing, so that requirements and goals for PM2.5 monitoring will be fulfilled. 　　The performance audit used independent instruments and standards to inspect the deviation between the monitoring value and the standard value (accuracy). 128 stations were completed in two years. The acceptance rate was 100%. In addition, 375 stations of procedure check for field operators were also included. And must follow up tracking the results of defects improvement. 　　A quality system check for laboratory refers to the organizational resources, processes and procedures to implement quality management. 24 Laboratory system audits and 4 inter-lab weighting comparisons have been accomplished in two years. All samples are within the criteria, indicating overall good inter-laboratory agreement between the test laboratories and QA-Laboratory. 　　The sampler collocation measurement is mainly based on the published method NIEA A205.11C by EPA Environmental analysis laboratory, to enhance the reliability of monitoring data. 245 field stations collocated comparisons were done in two years. 230 times valid comparisons were under circumstances of PM2.5 concentrations greater than 3 μg/m3. 0~±1 μg/m3 of concentration bias indicate a high credibility of PM2.5 manual monitoring data. 　　Data verification and validation were mainly focus on worksheet filling, concentration calculations and quality management of laboratory, to meet the requirement of NIEA method. 7,564 pieces of data validations were carried out in this project. Among these data, 152 were marked “invalid data”, and 30 were marked “not executed sample”. The overall rate of available data is 97.6%. 　　All defects from field performance audit and Laboratory check will be require to improve within certain days discussed in monthly routine data reviewing meeting, The EPA and this project will track situation of defects improvement.

Fine Particulate Matters, Field Check, Collocated Measurement