Grain size correction data for beta-dose rates
published by Guérin et al. (2012).
#' @format
A data.frame seven columns and sixteen rows. Column headers
are GrainSize, Q_K, FS_K, Q_Th, FS_Th, Q_U, FS_U.
Grain sizes are quoted in µm (e.g., 20, 40, 60 etc.)