• Sample 100 mL of the water to be analyzed and transfer it to a 200 mL beaker.
• Add a few drops of colored indicator (phenolphthalein for AT, bromocresol green or methyl orange for CAT)
• Place the conductivity cell and the glass electrode in the solution.
• Dose with a hydrochloric acid solution at 0.02 mol/L.
• The conductivity σ and the pH of the solution are measured as a function of the volume of hydrochloric acid added.

Remarks:
If we wish to determine AT and CAT using colorimetry, either two independent titrations can be carried out, or phenolphthalein can be added first followed by bromocresol green or methyl orange after the phenolphthalein is colorless.