Conversion between Moisture content (wet/fresh weight basis) and Moisture content (dry weight basis)

These functions convert from moisture content determined on wet/fresh weight basis to equivalent value on dry weight basis and back. MoistureNomograph plots the nomograph for these conversions.

dry2wet(mc)

wet2dry(mc)

MoistureNomograph(min, max, basis = c("wet", "dry"), horiz = FALSE)

Arguments

mc	Moisture content.
min	Minimum value of moisture content to be plotted in nomograph.
max	Minimum value of moisture content to be plotted in nomograph.
basis	The basis on which moisture content is estimated
horiz	If TRUE, nomograph is plotted horizontally.

Value

For wet2dry and dry2wet, the converted moisture content (%).

For MoistureNomograph, the nomograph as an object of class ggplot.

Details

Conversions between moisture content (%) determined on wet weight basis MC_wb and that on dry weight basis MC_db are computed based on the formulae Cromarty et al. (1982) as follows.

MC_db = ^{100 × MC_wb} ⁄ _{100 − MCwb}

MC_wb = ^{100 × MC_db} ⁄ _{100 + MCdb}

MC_wb = ^{[wi − w_f]} ⁄ _wi

MC_db = ^{[wi − w_f]} ⁄ _wf

Where, w_i is the initial weight and w_f is the final weight.

If the moisture content (mc) for conversion is beyond limits (0-50 % for wet2dry and 0-100 % for dry2wet), a warning is issued.

References

Cromarty AS, Ellis RH, Roberts EH (1982). The Design of Seed Storage Facilities for Genetic Conservation, Revised 1985 and 1990 edition. International Board for Plant Genetic Resources, Rome, Italy.

Examples

#----------------------------------------------------------------------------
# Moisture content (wet basis) to moisture content (dry basis)
#----------------------------------------------------------------------------
wet2dry(25)
#> [1] 33.33333
# Warning if moisture content is beyond limits (0-50 %)
wet2dry(60)
#> Warning: "mc" is beyond limits (0 < "mc" < 50).
#> [1] 150
wet2dry(-10)
#> Warning: "mc" is beyond limits (0 < "mc" < 50).
#> [1] -9.090909

#----------------------------------------------------------------------------
# Moisture content (dry basis) to moisture content (wet basis)
#----------------------------------------------------------------------------
dry2wet(30)
#> [1] 23.07692
# Warning if moisture content is beyond limits (0-100 %)
dry2wet(-10)
#> Warning: "mc" is beyond limits (0 < "mc" < 100).
#> [1] -11.11111
dry2wet(110)
#> Warning: "mc" is beyond limits (0 < "mc" < 100).
#> [1] 52.38095

#----------------------------------------------------------------------------
# Nomograph
#----------------------------------------------------------------------------
# Horizontal
MoistureNomograph(min = 0, max = 50, basis = "wet", horiz = TRUE)
MoistureNomograph(min = 0, max = 100, basis = "dry", horiz = TRUE)

# Vertical
MoistureNomograph(min = 0, max = 50, basis = "wet", horiz = FALSE)
MoistureNomograph(min = 0, max = 100, basis = "dry", horiz = FALSE)

# Nomograph is a "ggplot" object
nom <- MoistureNomograph(min = 0, max = 50, basis = "wet", horiz = TRUE)
library(ggplot2)
nom + geom_hline(aes(yintercept=30), colour = "red")
p <- "Scale for converting moisture content values\nbetween dry and wet basis"
cap <- "based on Cromarty et al., 1982"
nom + labs(title  = p, caption = cap) +
  theme(plot.title = element_text(hjust = 0.5))