True RMS
Updated 2026-10-27
Data records
- True RMS describes a measurement that computes the root-mean-square value of a waveform from its actual shape rather than by scaling a rectified average, so that the reading represents the heating value of the signal whatever its distortion.
- The term is written True RMS. Value: True RMS.
- A true RMS meter computes the root-mean-square value of the waveform and so reads the distorted currents drawn by nonlinear loads such as variable speed drives correctly, whereas an average-responding meter is calibrated for sine waves and reads a distorted waveform low or high.
Sources
- Electrical Testing Reference editorial taxonomy, Electrical Testing Reference editorial taxonomy of test methods, 2026-10 edition, Electrical Testing Reference. Held as: Own observation.
- Fluke learn article, What is true-RMS?, web page edition, Fluke. Held as: Public page. Publisher page
Changelog (6 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (gloss.true-rms.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.true-rms.definition) | |
| 2026-10-27 | created (gloss.true-rms.title) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.true-rms.title) | |
| 2026-10-27 | created (gloss.true-rms.usage) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.true-rms.usage) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"True RMS." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/glossary/true-rms/.
Test Instrument Reference, True RMS (Oct. 27, 2026), https://www.testinstrumentreference.com/glossary/true-rms/.
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title = {True RMS},
howpublished = {\url{https://www.testinstrumentreference.com/glossary/true-rms/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=True RMS |website=Test Instrument Reference |publisher=Test Instrument Reference |url=https://www.testinstrumentreference.com/glossary/true-rms/ |date=2026-10-27 |access-date=}}