Answer
$N_{1} = 320,000\ grains/inch^{2}$
Work Step by Step
Given:
ASTM grain size (n)= 6
Required:
grains per square inch without any magnification
Solution:
Using Equation 4.18, we find:
$N_{M}(\frac{M}{100})^{2} = 2^{n-1}$,
$N_{M}$ is the number of grains at magnification M; note, n is the ASTM grain size.
Since there is not any magnification, M = 1:
$N_{1}(\frac{1}{100})^{2} = 2^{6-1}$,
$N_{1} = 320,000\ grains/inch^{2}$
