Logarithmic Standard Deviation - 2nd moment

Description

Shows how much variation or dispersion from the average exists. Logarithmic mean size (1st moment) needs to be precalculated.

Related formulas

Variables

σ_ϕLogarithmic Standard deviation - 2nd moment (dimensionless)
fiCumulative weight percent of the i- particle size grade present (dimensionless)
miMid-point of the i- particle size grade present (dimensionless)
X_ϕLogarithmic Mean Size - 1st moment (dimensionless)