Capillary electrometer

{
  "id": "MLC-T-MET-004141",
  "term": "Capillary electrometer",
  "field": "Meteorology and atmospheric science",
  "definition": "An instrument for detecting and measuring small differences in electrical potential, historically used in atmospheric electricity research. It operates on the principle that the surface tension of a mercury meniscus in contact with an electrolyte changes in response to an applied voltage, causing the meniscus to move. This movement is observed with a microscope and calibrated to measure potential gradients, such as those found between different points in the atmosphere.",
  "url": "https://mlchart.com/terminology/meteorology/capillary-electrometer/"
}