conductance in SELECTED_OUTPUT

[zsszabo86]

I can see the Specific Conductance (µS/cm,  17°C) data in the PHREEQC .phr.out file, however I could not figure out if there is a way to include this data in the .txt file generated by SELECTED_OUTPUT. If there is a way, please share it. Thank you in advance!

[dlparkhurst]

The Basic function SC returns the specific conductance at the current temperature.

Updated documentation including all Basic functions (see The Basic Interpreter section) are available in the version 3 documentation in all distributions and at the following URL:

https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/phreeqc3-html/phreeqc3.htm

[dlparkhurst]

Just to add. Measured specific conductance is often reported as specific conductance at 25 C. The following is an approximation that converts the SC at the current temperature (SC) to specific conductance at 25 C.

10 sc25 = SC/(1 + 0.021 * (TC - 25))

[zsszabo86]

Dear David
Thank you for the reply.
However, I am not sure how to write the code.. Where should I use SC basic function to make phreeqc to add SC data to printed output txt file?
Do I need to use PRINT keyword somewhere after SELECTED_OUTPUT?
I went through the documentation but I do not see any example for this.

[dlparkhurst]

The specific conductance is automatically printed in the output file (usually the .out file), but only for databases that have -Dw (diffusion coefficients) in the SOLUTION_SPECIES definitions. The database files with -Vm are pitzer.dat, phreeqc.dat, and Amm.dat.

[jaferrari]

I did it this way:

CALCULATE_VALUES
SC_T25
-start
  10 sc25 = SC/(1 + 0.021 * (TC - 25))
  20 SAVE sc25
-end


SELECTED_OUTPUT 1 specific conductance
    -file                 KIN_CACO3.csv
    -time                 true
    -pH                   true
    -totals               Ca  C  Calcite
    -molalities           (CO2)2  CaCO3  HCO3-
    -saturation_indices   calcite
    -gases                CO2(g)
    -kinetic_reactants    Calcite
    -calculate_values     SC_T25