uncertAirDensity {masscor}

Uncertainties in air density calculations

Description

Propagates the uncertainty of environmental conditions measurements to estimated values of air densities calculated using the function airDensity() with models 'CIMP2007' y 'CIMP.approx' function. Uncertainty arising from to the chosen model itself is considered. Calculations are made according to the Guide to the Guide to the expression of uncertainty in measurement (GUM, JCGM, 2008) as implemented by the package metRology (Ellison, 2018).

Usage

uncertAirDensity(model = "CIMP2007", Temp = 20, p = 1013.25, h = 50,
  u_Temp = 2.9, u_p = 10.1, u_h = 11.3, unitsENV = c("deg.C", "hPa",
  "%"), plot = TRUE, printRelSD = TRUE)

Arguments

model

model to use for air density calculation. Must be one of 'CIMP2007' (default), 'CIMP.approx' or 'Jones1978'. See See Details for references.

Temp

ambient temperature in weighing room.

p

barometric pressure in weighing room.

h

relative humidity in weighing room.

u_Temp

standard uncertainty of temperature measurement

u_p

standard uncertainty of barometric pressure measurement

u_h

standard uncertainty of relative humidity

unitsENV

character vector of length three with the units of p, Temp and h. Default is c('deg.C', 'hPa', '%'). See unitsENV below for more options.

plot

logical. If TRUE (the default), the relative uncertainty contributions are shown in a barplot.

printRelSD

Logical. If TRUE (the default), a short statement indicating relative standard uncertainty of the air density estimation is printed.

Value

A numeric value of standard uncertainty of calculated air density in g~cm^{-3}.

unitsENV

Temperature units (Temp) can be either 'deg.C' (for Celsius degrees) or 'K'. Pressure units (p) can be any of 'mmHg', 'Pa', 'hPa' or 'kPa'. Relative humidity (h) can be expressed as fraction ('frac') or as percentage ('%'). A typical arrangement for the parameter unitsENV would be c('deg.C', 'hPa', '%').

References

Picard, A; Davis, R S; Gläser, M; Fujii, K (2008). Revised formula for the density of moist air (CIPM-2007). Metrologia, 45(2), 149–155. doi:10.1088/0026-1394/45/2/004

Harris, G. (2019). Selected Laboratory and Measurement Practices and Procedures to Support Basic Mass Calibrations. SOP 2 - Recommended Standard Operating Procedure for Applying Air Buoyancy Corrections. National Institute of Standards and Technology (NIST). doi:10.6028/NIST.IR.6969-2019

BIMP JCGM (2008) Evaluation of measurement data — Guide to the expression of uncertainty in measurement.

Stephen L R Ellison. (2018). metRology: Support for Metrological Applications. R package version 0.9-28-1. https://CRAN.R-project.org/package=metRology

See Also

airDensity()

Examples

 uncertAirDensity(model = 'CIMP2007',
                  Temp = 20, p = 1013.25, h = 50,
                  u_Temp = 0.29, u_p = 1.01, u_h = 11.3)