Research Engineer, Engineering Materials Laboratory, University of California, Berkeley, Calif
Pages: 14 Published: Jan 1941
This paper describes a method of test and a hydrometer with a new type of scale which have been developed for measuring the fineness of powdered materials. The hydrometer scale consists of units of surface area rather than the customary units of density. The method of test is generally similar to that usually employed when fineness determinations are made through the use of a hydrometer, but is simplified considerably.
The theory and equations on which the surface-increment scale is based are discussed. Brief methods of computation are illustrated which, while considerably more rapid than those customarily used, yield closely comparable results. Comparisons are made between results obtained by the brief methods of calculation and (1) those obtained by the more detailed hydrometer method used heretofore, and (2) those obtained through the use of the turbidimenter in accordance with the A.S.T.M. Tentative Method of Test for Fineness of Portland Cement by Means of the Turbidimeter (C 115–38 T).
Paper ID: STP43896S