scope:

PREFACE

The previous edition of Chapter 13, "Diffusivity," was prepared in 1964. Since that time considerable new data and a number of improved correlation techniques for diffusivities have been published. Thus, in 1979 a complete revision of the diffusivity chapter was begun. The resulting chapter covers more types of systems and provides methods which yield lower average errors than the previously published chapter. Detailed results for all the evaluations used to select the contents of the revised chapter are given in Documentation Report 13-80 available from University Microfilms, Ann Arbor, Michigan.

Work on this chapter was carried out by N. O. Umesi in conjunction with the project directors, R. P. Danner and T. E. Daubert. The work was reviewed periodically by the Subcommittee on Technical Data of the American Petroleum Institute.