Accession Number : AD0722333

Title :   Two-Dimensional Systematic Point Count for Volume Fraction Analysis from a Poisson Theoretic Approach.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Grimes,James P. ; Navid,Burton N.

Report Date : 31 MAR 1971

Pagination or Media Count : 16

Abstract : In many fields of scientific investigation, the structure of cellular aggregates or random arrays of discrete particles imbedded in some solid is observed on a two-dimensional section and inferences drawn therefrom as to the real structure in three dimensions. A fast, reliable method for the quantitative determination of the percentages of these micro- or macroconstituents would be of great benefit for structural studies in the solid state. One of the techniques most often used for the estimation of volume fractions from measurements made on a random two-dimensional section is that of the two-dimensional systematic point count, i.e., that the fractional number of regularly dispersed points falling within the boundaries of a two-dimensional feature on a plane provides an unbiased estimate of the areal fraction, and consequently of the volume fraction, of that feature. The two-dimensional systematic point count is demonstrated here from a Poisson theoretic approach. In addition, two methods of application are investigated: one using a normal approximation, the other, the Poisson distribution. The relationship between the latter and the point-count precedure is also indicated. (Author)

Descriptors :   (*STATISTICAL ANALYSIS, MATHEMATICAL PREDICTION), (*PARTICLES, COUNTING METHODS), STATISTICAL DISTRIBUTIONS, CONFIDENCE LIMITS, PROBABILITY, SAMPLING, QUANTITATIVE ANALYSIS, PETROLOGY

Subject Categories : Statistics and Probability
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE