respirometry (version 2.0.0)

conv_o2: Convert between units of oxygen partial pressure and concentration

Description

Unfortunately, a consensus on the best way to express how much oxygen is in water has not been formed to date. Until then, this function converts between all commonly used forms of dissolved O2 measurements.

Usage

conv_o2(
  o2 = 100,
  from = "percent_a.s.",
  to = "all",
  temp = 25,
  sal = 35,
  atm_pres = 1013.25
)

Arguments

o2

a numeric vector of the O2 value(s). Default is 100.

from

a string describing the unit used to measure o2. Default is "percent_a.s." Options are:

• percent_a.s. (percent air saturation)

• percent_o2

• hPa

• kPa

• torr

• mmHg

• inHg

• mg_per_l

• ug_per_l

• umol_per_l

• mmol_per_l

• nmol_per_ml

• ml_per_l

• mg_per_kg

• ug_per_kg

• umol_per_kg

• mmol_per_kg

• ml_per_kg

• volumes_percent

to

a single string either describing the unit to which the conversion should be conducted (options are the same as in from), or the string "all" to return all units.

temp

temperature (°C). Default is 25 °C.

sal

salinity (psu). Default is 35 psu.

atm_pres

atmospheric pressure (mbar). Default is 1013.25 mbar.

Author

Matthew A. Birk,

Details

Conversions are based on relationships and values from the package marelac which utilizes saturation values from Weiss 1970.

References

Weiss R. 1970. The solubility of nitrogen, oxygen, and argon in water and seawater. Deep-Sea Research. 17:721-735.

Examples

conv_o2(o2 = 50)
conv_o2(o2 = 1:50, from = "umol_per_l", to = "ml_per_l", temp = 10, sal = 0,
	atm_pres = 1100)
conv_o2()[c('mmHg','kPa')]