Hygroscope

{
  "id": "MLC-T-MET-006373",
  "term": "Hygroscope",
  "field": "Meteorology and atmospheric science",
  "definition": "A simple device that indicates changes in atmospheric humidity without necessarily providing a quantitative measurement. Early hygroscopes often used materials like human hair or certain salts that visibly react to moisture variations. While not as precise as a hygrometer, it can show whether the air is becoming more or less humid.",
  "see_also": [
    "chemical hygrometer"
  ],
  "url": "https://mlchart.com/terminology/meteorology/hygroscope/"
}