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Convert CO2 measurements from gas analyzer data

Source: R/convert_unit.R
convert_unit_co2.Rd

Converts CO2 measurements from gas analyzer data into standardized units, with options for temperature correction. It can process both single measurements and vectors of measurements.

The function implements standard gas analysis conversions and can optionally apply temperature corrections using a Q10 = 2 approach (metabolic rate doubles for every 10°C increase).

Usage

convert_unit_co2(
  co2_value,
  flow_rate,
  unit_flowrate = "mL/min",
  unit_input_co2 = "umol/mol",
  unit_output_time = "h",
  unit_output_vol = "mL",
  from_temperature = NULL,
  to_temperature = NULL
)

Arguments

co2_value

Numeric vector. The differential CO2 value(s) from gas analyzer (default in μmol/mol or ppm)

flow_rate

Numeric. The flow rate of gas though the system.

unit_flowrate

Character. Flow rate unit, either "mL/min" or "mL/h". Default: "mL/min"

unit_input_co2

Character. Input CO2 unit, either "uM/M" or "umol/mol" (both equivalent to ppm). Default: "umol/mol"

unit_output_time

Character. Desired time unit for the output rate, one of "s", "min", or "h". Default: "min"

unit_output_vol

Character. Desired volume unit for the output, either "mL" or "uL". Default: "mL"

from_temperature

Numeric. Source temperature in Celsius. Only required if metabolic temperature correction is desired (must be provided with to_temperature).

to_temperature

Numeric. Optional target temperature in Celsius. Must be provided together with from_temperature if temperature correction is desired.

Value

Numeric vector of converted CO2 values in the specified output units

Details

The function performs the following conversions:

  1. Converts CO2 measurements from ppm (μmol/mol) to fractions

  2. Optionally applies temperature correction using Q10 = 2

  3. Converts to desired output units (μL conversion is direct volume conversion)

Temperature correction uses the formula: correction_factor = 10^((to_temperature - from_temperature) * (log10(2)/10))

References

Temperature correction method based on standard Q10 = 2 approach, where metabolic rate doubles for every 10°C increase in temperature.

Examples

# Basic usage
convert_unit_co2(
  co2_value = 100,
  flow_rate = 1300,
  unit_output_time = "h",
  unit_output_vol = "uL"
)
#> [1] 7800


# With temperature correction
convert_unit_co2(
  co2_value = 100,
  flow_rate = 200,
  from_temperature = 17, # Experiment temperature
  to_temperature = 25,   # Standard temperature
  unit_output_vol = "uL",
  unit_output_time = "min"
)
#> [1] 34.82202

# Processing a sequence of measurements
co2_values <- c(95, 98, 100, 103, 99)
convert_unit_co2(
  co2_value = co2_values,
  flow_rate = 200,
  unit_output_vol = "mL",
  unit_output_time = "min"
)
#> [1] 0.0190 0.0196 0.0200 0.0206 0.0198