Hair hygrometer

{
  "id": "MLC-T-MET-006148",
  "term": "Hair hygrometer",
  "field": "Meteorology and atmospheric science",
  "definition": "A type of hygrometer that measures atmospheric humidity based on the principle that human or animal hair changes length in response to variations in relative humidity. As humidity increases, the hair absorbs moisture and lengthens, and as it decreases, the hair contracts. This change in length is mechanically amplified and displayed on a dial, providing a direct reading of relative humidity.",
  "url": "https://mlchart.com/terminology/meteorology/hair-hygrometer/"
}