"This manual presents a method, Constant Sampling Rate (CSR), which allows determination of stationary source PM10 emissions with hardware similar to that used for Methods 5 or 17. The operating principle of the method is to extract a multipoint sample so that errors due to spatial variation of particle size and anisokinetic sampling are kept within predetermined limits. Current specifications were designed to limit error due to spatial variations to 10%. The maximum allowable error due to anisokinetic sampling is «20%; in essentially all sampling situations, cancellation of sampling error will limit overall anisokinetic sampling error to much less than this value. This manual specifically addresses the use of the CSR methodology for determination of stationary source PM10 emissions. Material presented in this manual includes: calibration of sampling train components, pretest setup calculations, sample recovery, test data reduction, and routine equipment maintenance."