HARDNESS-MEASURING COMPOSITION, HARDNESS-MEASURING REAGENT KIT, HARDNESS MEASUREMENT METHOD, AND FOULING PREVENTION METHOD FOR HARDNESS-MEASURING DEVICE

摘要

Provided is a hardness-measuring composition that is used for prevention of measurement error of the measurement unit of a water hardness-measuring device by deposition of the staining components contained in sample water.;The hardness-measuring composition comprises a colorant containing Eriochrome Black T and/or Calmagite and a sulfate ester-type anionic surfactant.