Campbell-Stokes recorder

{
  "id": "MLC-T-MET-010417",
  "term": "Campbell-Stokes recorder",
  "field": "Meteorology and atmospheric science",
  "definition": "An instrument that measures the duration of bright sunshine in a day by focusing sunlight onto a specially designed card. A solid glass sphere acts as a lens, concentrating the sun's rays to burn a trace on a paper card held in a spherical bowl. The length of the burn track, which follows the sun's path across the sky, is proportional to the hours of direct solar radiation.",
  "url": "https://mlchart.com/terminology/meteorology/campbell-stokes-recorder/"
}