Sequential sampling plan for Federal Standard 209

A sequential sampling plan is developed to match the operating characteristic (OC) curve of the Federal Standard 209D single sampling plan as a possible revision to the Standard. The sequential sampling plan gives virtually identical probabilities of passing or failing that a single sample gives. However, the sequential plan would save 80 percent of the sampling time for very clean air, about 35 percent of the sampling time for air that is just at the Class Limit, and more than 80 percent of the sampling time for air that is more than 2.5 times as contaminated as the Class Limit.