Calculates charge balances based on ALS formula. Note: Original EMS charge balances, anion sums and cation sums have been omitted.
Arguments
- d
Data set formatted for AquaChem (output of
rems_to_aquachem())
Details
Potential changes in workflows over the years have made it difficult to ascertain exactly how charge balances were calculated in older samples. This resulted in discrepancies between EMS and locally calculated charge balances. Therefore for consistency, we calculate charge balances for all samples using the ALS formula below.
One difference between this calculation and that of ALS, is that we use more significant digits when calculating MEQ.
anion sum = Cl_meq + SO4_meq + F_meq + NO3_meq + NO2_meq + Means_Alk_meq
cation sum = Ca_meq + Mg_meq + Na_meq + K_meq + Al_diss_meq + Cu_diss_meq + Fe_diss_meq + Mn_diss_meq + Zn_diss_meq + NH4_meq + (10 ^ (-pH_lab)) * 1000
Charge balance = 100 x (Cation Sum - Anion sum) / (Cation Sum + Anion Sum)
Missing values are ignored (ie. generally treated as 0). However, if all
values for cations or anions are missing the charge balance is NA.