This International Standard specifies a method for determining the pH value in rain, drinking and mineralwaters, bathing waters, surface and ground waters, as well as municipal and industrial waste waters, andliquid sludge, within the range pH 2 to pH 12 with an ionic strength below I = 0,3 mol/kg (conductivity:γ25 ℃ < 2 000 mS/m) solvent and in the temperature range 0 ℃ to 50 ℃.
EN ISO 10523:2012 Referenced Document
ISO 3696 Water for analytical laboratory use; Specification and test methods
ISO 4796-2 Laboratory glassware - Bottles - Part 2: Conical neck bottles