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International Prototype of the Kilogram

Object that defined the kilogram (1889–2019)

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionSep 12, 2026
Entity authoritySource title only
Source-derived summary

The International Prototype of the Kilogram is an object whose mass was used to define the kilogram from 1889, when it replaced the Kilogramme des Archives, until 2019, when it was replaced by a new definition of the kilogram based entirely on physical constants. During that time, the IPK and its duplicates were used to calibrate all other kilogram mass standards on Earth.

Editorial summary

“International Prototype of the Kilogram” enters the record as object that defined the kilogram (1889–2019). Crown Archives preserves that source wording while asking what International, Prototype and Kilogram can confirm, complicate or overturn.

Editorial reviewA practical starting point whose main value is the path it opens into stronger specialist and primary sources. The current lead gives the account dated anchors—1889, 2019—that can be checked directly. The selected authority fields contribute no independent date. Its strongest next move is a source search built around International, Prototype and Kilogram.
Editorial analysis

Why this record matters

“International Prototype of the Kilogram” is worth following because a concise public description often conceals a longer documentary argument. Here, International, Prototype and Kilogram provides the most credible route into that argument.

Evidence profile

Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 12, 2026. The first chronological checks are 1889 and 2019.

Critical limits

Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

How to read it

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

Best used for
  • Subject orientation
  • Search vocabulary
  • Locating named sources
Verify next

The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “International Prototype of the Kilogram”, its source revision and the description used here.
  2. Expand the search: follow International Prototype of the Kilogram primary sources, International Prototype of the Kilogram archive and International research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “International Prototype of the Kilogram”?
  2. What terminology or title could unlock a more precise catalogue search?
  3. Which institution is responsible for the underlying evidence?
Subject index

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Source & attribution

This entry incorporates text from “International Prototype of the Kilogram” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.