Primary pH standards

{
  "id": "MLC-T-CHM-009439",
  "term": "Primary pH standards",
  "field": "Chemistry",
  "definition": "Aqueous solutions of precisely defined composition and known pH values, used for calibrating pH meters and electrodes. These solutions are prepared from high-purity chemicals and have pH values that are stable and reproducible over time. Their pH is determined by a primary method, such as the Harned cell without liquid junction.",
  "subject": "Analytical Chemistry",
  "see_also": [
    "liquid junction"
  ],
  "references": [
    "Orange Book, 2nd ed., p. 19 (https://media.iupac.org/publications/analytical_compendium/)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/primary-ph-standards/"
}