Primary time standard

{
  "id": "MLC-T-IND-004503",
  "term": "Primary time standard",
  "field": "Industrial and trades",
  "definition": "A high-precision frequency standard that determines the correct time and frequency without being calibrated against any other external reference. These standards are based on the fundamental quantum properties of atoms, most commonly caesium-133, which provides the modern definition of the second. National metrology institutes, such as NIST in the United States, maintain primary time standards like atomic fountain clocks to generate and distribute Coordinated Universal Time (UTC).",
  "subject": "Electrical engineering",
  "translations": {
    "de": "Primärnorm",
    "es": "estándar de tiempo primario",
    "fr": "étalon de temps primaire"
  },
  "url": "https://mlchart.com/terminology/industrial/primary-time-standard/"
}