eps_water: Calculate Permittivity of Water Dependend on Temperature

In TillF/FDR2soilmoisture: Processing data of FDR-measurements to obtain soil moisture

Calculate Permittivity of Water Dependend on Temperature

Description

Using one of the equations from Weast86, Uematsu1980 or IAPWS Formulations for Electrostatic Properties of Water, the function calculates the permittivity/epsilon [-] of water for a given temperature at normal pressure. The not-default equations require the installation of the iapws-package (see details).

Usage

eps_water(T, equ = "Weast86")

Arguments

T	Temperature T of water in degree Celsius [*C]
equ	Equation to be used. Must be one of "Weast86" (default), "Uematsu1980" or "iapws"

Details

Two equations are implemented:

• "Weast86" (Weast, R.C., 1986):

  \epsilon = 78.54 * (1 - (4.5791 * 10^{-3})*(T-25) + 1.19*10^{-5} * (T-25)^2 - 2.8 * 10^{-8} * (T-25)^3

• "Uematsu1980" (Journal of ..., 1980):

  \epsilon = 1 + \frac{A}{T_2} * \rho_2 + (\frac{B}{T_2} + C + D * T_2) * \rho_2^2 + (\frac{E}{T_2} + F * T_2 + G * T_2^2) * \rho_2^3 + (\frac{H}{T_2^2} + \frac{I}{T_2} + J) * \rho_2^4

  with T_2 = \frac{T}{298.15} [\frac{K}{K}], \rho_2=\rho/1000 [\frac{kg*m^{-3}}{kg*m^{-3}}] and A=7.62571, B=244.003, C=-140.569, D=27.7841, E=-96.2805, F=41.7909, G=-10.2099, H=-45.2059, I=84.6395, J=-35.8644.

  The temperature dependend density of water \rho is calculated usinf the iapws package by Jonathan Debove (install.packages("iapws")).

• "iapws" (Debove J, 2022): Formulations for the thermodynamic and transport properties released by the International Association for the Properties of Water and Steam (IAPWS) and implemented in the iapws package by Jonathan Debove (install.packages("iapws")).

Value

Permittivity of water [-]

Author(s)

Jakob Terschluesen

References

Debove J (2022). _iapws: Formulations of the International Association for the Properties of Water and Steam_. R package version 1.1, <https://CRAN.R-project.org/package=iapws>.

Journal of Physical and Chemical Reference Data 9, 1291 (1980); https://doi.org/10.1063/1.555632

Weast, R.C. CRC Handbook of Physics and Chemistry, 67th ed.; CRC Press: Boca Raton, FL, USA, 1986.

See Also

https://cran.r-project.org/package=iapws

Examples

#calculate Permittivty of water at 20.5 degree
T=20.5
eps_water(T,equ = "Weast86")
eps_water(T,equ = "Uematsu1980")

#only if package iapws is installed
if(require("iapws", quietly = TRUE)){
  eps_water(T, equ = "Uematsu1980")
}

if(require("iapws", quietly = TRUE)){
  eps_water(T, equ = "iapws")
}

T=seq(5,40,5)
eps_water(T,equ = "Weast86")
eps_water(T,equ = "Uematsu1980")

#only if package iapws is installed
if(require("iapws", quietly = TRUE)){
  eps_water(T, equ = "Uematsu1980")
}

if(require("iapws", quietly = TRUE)){
  eps_water(T, equ = "iapws")
}

TillF/FDR2soilmoisture documentation built on Dec. 6, 2024, 9:30 a.m.