R: Lognormal aerosol number and mass concentration conversion

n2m.lnorm {heR.IndoorAir}

R Documentation

Lognormal aerosol number and mass concentration conversion

Description

Function to convert a lognormally distributed particle number concentration to a lognormally distributed particle mass concentration, or vice-versa

Usage

n2m.lnorm(gm=1, gsd=exp(1), norm=1, n2m=TRUE, density=1, plot=FALSE)

Arguments

`gm`	the geometric mean
`gsd`	the geometric standard deviation
`norm`	the normalization constant: total mass or total counts, see below
`n2m`	logical, whether to convert number to mass or vice-versa
`density`	particle density in grams per cubic cm
`plot`	logical, whether to plot the two distributions on a log-probability plot or not

Details

Note: Aerosol = airborne particulate matter

The normalizing factor norm is either the total number of particles per cubic cm or the total mass per cubic meter (i.e., the integral of the unnormalized particle size distribution by either number or mass).

This function assumes that particles are spherically shaped.

Particle number concentration is in counts per cubic centimeter.
Particle mass concentration is in micrograms per cubic meter.
Particle density is in grams per cubic centimeter.

Value

A list giving the converted geometric mean, standard deviation, and normalization constant

Author(s)

Neil E. Klepeis
nklepeis@uclink.berkeley.edu
http://socrates.berkeley.edu/~nklepeis