The report gives results of a survey to identify all equations required to represent particle size data according to each of three particle diameter definitions: Stokes, classical aerodynamic, and aerodynamic impaction (or Lovelace diameter). Although the particle diameter definitions themselves are relatively simple, inconsistencies were found among various investigations in the use of particle size definitions, particularly in nomenclature. It is not always clear from the descriptions of various authors which definition is intended. The present study presents a consistent set of definitions and equations for use in interpreting particle size and impactor data such as that found in EPA's Fine Particle Emissions Information System (FPEIS) data base. The equations may also be useful to readers of fine particle sampling reports who may wish to convert the data from one definition to a more convenient one.

Work performed under Contract 68-02-2609. Prepared under contract no. 68-02-2084, SRI project 4432. Issued Nov. 1977. Includes bibliographical references.

This report presents the results of a measurement survey to identify all equations required to represent particle size data according to each of three particle diameter definitions--Stokes, classical aerodynamic, and aerodynamic impaction (or Lovelace diameter). Although the particle diameter definitions themselves are relatively simple, inconsistencies were found among various investigations in the use of particle size definitions, particularly in nomenclature. It is not always clear from the descriptions of various authors which definition is intended. The present study presents a consisten set of definitions and equations for use in interpreting particle size and impactor data such as that found in the Fine Particle Emissions Information System (FPEIS) data base. The equations may also be useful to readers of fine particle sampling reports who may wish to convert the data from one definition to a more convenient one.