Calculate the effective volume of a respirometer

Source: R/eff_vol.R

Calculate the effective volume of a respirometer.

eff_vol(resp_vol = NULL, spec_vol = NULL, spec_mass = NULL,
  spec_density = NULL, t = NULL, S = NULL, P = 1.013253)

Arguments

resp_vol

numeric (L). Volume of the respirometer or loop.
spec_vol

numeric (L). Displacement volume of the specimen. Enter either this or spec_mass.
spec_mass

numeric (kg). Mass of the specimen. Enter either this or spec_vol.
spec_density

numeric (kg/m^3). Density of the specimen. Optional. Used to convert spec_mass to a volume.
t

numeric (°C). Water temperature. Optional. Used to calculate density if spec_density is left NULL.
S

numeric (ppt). Water salinity. Optional. Used to calculate density if spec_density is left NULL.
P

numeric (bar). Atmospheric pressure. Optional. Used to calculate density if spec_density is left NULL. Defaults to 1.013253.

Details

Adjusts the known water volume of an aquatic respirometer (or respirometer loop) for the volume of the specimen. This can be entered either as a straight displacement volume of the specimen for simple subtraction (spec_vol), or as a mass (spec_mass), in which case the spec_density is required to calculate the displacement volume. The spec_density can be entered as a value in kg/m^3. Alternatively, it can be assumed the specimen is the same density as the water (this is the case if it is neutrally buoyant). This can be entered as the spec_density value, for example typical seawater density is around 1026 kg/m^3. Alternatively it can be calculated internally, in which case temperature (t) and salinity (S) are required, along with atmospheric pressure (P). Note, that since P has a negligible effect on water density within the typical ranges experienced at sea level, the default of 1.013253 bar is used unless otherwise specified.

Inputs

Inputs must be in SI units:

  • resp_vol and spec_vol in L

  • spec_mass in kg

  • spec_density in kg/m^3

  • t in °C

  • S in ppt

  • P in bar (Defaults to 1.013253)

Output

Output is a single numeric value for the effective volume in L.

See also

spec_density

Examples

## Simple displacement volume subtraction.
eff_vol(resp_vol = 1, spec_vol = 0.1)
#> Calculating Effective Volume as resp_vol minus spec_vol. 
#>  All other inputs IGNORED. 
#> [1] 0.9

## Mass & density to volume subtraction.
eff_vol(resp_vol = 1, spec_mass = 0.2, spec_density = 1026)
#> [1] 0.8050682

## Mass, with t, S used to calculate water density
eff_vol(resp_vol = 1, spec_mass = 0.2, t = 10, S = 35)
#> [1] 0.805225