Ringelmann chart

{
  "id": "MLC-T-MET-010724",
  "term": "Ringelmann chart",
  "field": "Meteorology and atmospheric science",
  "definition": "A series of charts used to visually estimate the density or opacity of smoke emitted from industrial stacks. Each chart consists of a grid of black lines on a white background, with varying line thickness and spacing to represent different shades of gray. Observers compare the smoke plume to the charts to assign a Ringelmann number, indicating the level of particulate emissions.",
  "url": "https://mlchart.com/terminology/meteorology/ringelmann-chart/"
}