Capacitance
Updated 2026-10-27
Data records
- Expressed in SI base units, the farad equals the fourth power of the second times the square of the ampere divided by the square meter and the kilogram. Value: m-2 kg-1 s4 A2.
- Capacitance is the property of two conductors separated by a dielectric that relates the electric charge stored on them to the voltage between them; for a fixed geometry, a larger capacitance stores more charge for the same voltage.
- Capacitance is read by power factor test sets on insulation systems such as bushings, windings and cables, by multimeters with a capacitance function and by LCR bridges on discrete components, and by motor circuit analyzers on the winding-to-ground insulation of machines.
- The capacitance values met in electrical testing run from the picofarad, typical of a condenser bushing or a short length of cable, through the nanofarad to the microfarad, typical of a long cable run or the winding-to-ground insulation of a large machine; the farad itself is far larger than any of these.
- In the NIST Guide to the SI, the farad, symbol F, is the SI coherent derived unit of capacitance and is expressed in other SI units as the coulomb per volt. Value: F.
Sources
- Electrical Testing Reference editorial taxonomy, Electrical Testing Reference editorial taxonomy of test methods, 2026-10 edition, Electrical Testing Reference. Held as: Own observation.
- NIST SP 811, NIST Guide to the SI, Chapter 4: The Two Classes of SI Units and the SI Prefixes, web page updated 2025-08-18 edition, NIST. Cited: clause Table 3. Held as: Government work. Publisher page
Changelog (11 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (qty.capacitance.base-units) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (qty.capacitance.base-units) | |
| 2026-10-27 | created (qty.capacitance.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (qty.capacitance.definition) | |
| 2026-10-27 | created (qty.capacitance.measured-by) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (qty.capacitance.measured-by) | |
| 2026-10-27 | created (qty.capacitance.submultiples) | |
| 2026-10-27 | revised (qty.capacitance.submultiples) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (qty.capacitance.submultiples) | |
| 2026-10-27 | created (qty.capacitance.unit) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (qty.capacitance.unit) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Capacitance." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/quantities/capacitance/.
Test Instrument Reference, Capacitance (Oct. 27, 2026), https://www.testinstrumentreference.com/quantities/capacitance/.
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title = {Capacitance},
howpublished = {\url{https://www.testinstrumentreference.com/quantities/capacitance/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=Capacitance |website=Test Instrument Reference |publisher=Test Instrument Reference |url=https://www.testinstrumentreference.com/quantities/capacitance/ |date=2026-10-27 |access-date=}}