Bifilar electrometer

{
  "id": "MLC-T-MET-003905",
  "term": "Bifilar electrometer",
  "field": "Meteorology and atmospheric science",
  "definition": "An instrument designed to measure small electric potentials or charges by observing the repulsion between two parallel conducting fibers, such as quartz or metal-coated threads. When a charge is applied, the fibers, suspended under tension, repel each other and move apart; the magnitude of the separation is proportional to the square of the voltage. This device was historically used in atmospheric electricity research, including measurements of the atmospheric potential gradient and the charge on raindrops, before being superseded by more modern electronic instruments.",
  "see_also": [
    "unifilar electrometer"
  ],
  "url": "https://mlchart.com/terminology/meteorology/bifilar-electrometer/"
}