INTERLABORATORY TEST FOR EXTERNAL QUALITY-CONTROL .1. SIGNIFICANCE OFTHE EXTERNAL QUALITY-CONTROL

Occasionally executed interlaboratory tests in the field of particulat e matter analysis have shown that existing methods of analysis are lab orious, inadequately described and the laboratories often are not suff iciently qualified. Therefore, quality control and proficiency testing is required. The quality control scheme in air pollution analysis con sists of measures related to the analytical method and the users of th e method. Four quality control levels will be characterized and the re levance of interlaboratory tests for these levels will be outlined. Th ey reflect the state of quality of the analytical procedure for the re spective measuring task. A survey will be given of air pollution inter laboratory tests performed in Germany.