On the trivariate volume equation

Abstract

The form class volume equation is most accurate volume equation, but the main obstacle to their accurate use is the difficulty, in estimating the upper diameter. If this difficulty is eliminated, we may widely use this volume equation. This paper presents a method for estimating form class by use of a lower diameter.
We have following results.
(1) By making use of the diameter at 1.8m above average ground level, we have same precision with the use of the diameter at half height.
(2) Equation (X) has the best precision.
(3) The form class volume equation has 2.5 times precision than the bivariate volume equation.