ABSTRACT
The original 209 standard was issued in December 1963, revised to 209A in August 1966, revised again to 209B in April 1973, and then 209B was amended in May 1976 to add a Class designation of 1000. The next revision was 209C dated October 1987 and finally, 209D, June 1988 which is simply a typographically corrected version of 209C. This chapter reviews the content and interpretation of the new standard (209D) more completely than previous reviews have done. Monitoring requirements are identical in the sections of class, concentrations, sizes, other classes and sizes, and calibration, but are different in the sections of frequency, volumes, volumes at other sizes, location and number of samples, methods and equipment, and analysis. In monitoring, these are to be specified by the user in a Monitoring Plan. Two items unique to monitoring are mentioned explicitly. Calibrations are to include both sensitivity to particle size and airflow rate.
