National standard barometer

{
  "id": "MLC-T-MET-007476",
  "term": "National standard barometer",
  "field": "Meteorology and atmospheric science",
  "definition": "A highly accurate barometer maintained by a national meteorological service or standards laboratory, serving as the primary reference for calibrating other barometric instruments. This instrument is typically a precision mercury barometer, carefully controlled for temperature and gravity effects. All other barometers used for weather observations within a country are ultimately traceable to this standard.",
  "url": "https://mlchart.com/terminology/meteorology/national-standard-barometer/"
}