For determination of acidity by Digital Titrator titration, with Methyl Orange (using bromphenol blue indicator) and Phenopthalein endpoints. Hach Methods 8201 (Methyl Orange) and 8202 (Phenolpthalein). Ranges: 10-160 and 1000-4000 mg/L as CaCO3. Reagent Set includes: Bromphenol Blue Powder Pillows, Phenolphthalein Powder Pillows and two Sodium Hydroxide Cartridges (0.1600 N and 1.600N). Approximately 40 - 100 tests