Secondary instrument

{
  "id": "MLC-T-MET-008744",
  "term": "Secondary instrument",
  "field": "Meteorology and atmospheric science",
  "definition": "An instrument whose calibration is determined by comparing its measurements against those of a primary or reference standard instrument. Unlike a primary standard, which is calibrated based on fundamental physical principles, a secondary instrument's accuracy is traceable to that higher-tier standard. Barometers used at weather stations are secondary instruments calibrated against a national standard barometer.",
  "url": "https://mlchart.com/terminology/meteorology/secondary-instrument/"
}