{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.unit-of-measurement","code":"thing-q47574","url":"https://ver.cy/models/thing/q47574/","name":"unit of measurement","alternateNames":["look","type of year","typed page","unit of mass density","unit of power","United States Pharmacopeia unit","non-SI unit","off-system measurement unit","multiple of a unit","unit of solid angle","unofficial unit of measurement","metric unit"],"kind":"thing","status":"published","version":"0.2.0-wave.1","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.QLT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A definite magnitude of a quantity, defined and adopted by convention, used as a standard for measurement, such as the metre, kilogram, second or pharmacopoeia units.","purpose":"Let an agent handle units by quantity, system, definition and conversion, and never report a number without a unit.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Standard magnitude of a quantity","Organised in systems","SI is the international system","Some units are domain-specific"],"structure":{"bundles":[{"id":"definition","name":"Definition","description":"Which unit.","layers":[{"id":"unit","name":"Unit","description":"Name and symbol.","findings":[{"id":"unit-finding","name":"Unit","description":"Unit identity.","questions":[{"text":"Which unit, with which symbol?","kind":"definition"},{"text":"What quantity does it measure?","kind":"definition"}]}]},{"id":"system","name":"System","description":"SI or other.","findings":[{"id":"system-finding","name":"System","description":"Unit system.","questions":[{"text":"Which system does it belong to?","kind":"definition"},{"text":"How is it defined?","kind":"provenance"}]}]}]},{"id":"conversion","name":"Conversion","description":"Between units.","layers":[{"id":"factor","name":"Factor","description":"Exact factor.","findings":[{"id":"factor-finding","name":"Factor","description":"Conversion factor.","questions":[{"text":"What is the exact factor to SI?","kind":"measurement"},{"text":"Is it exact or approximate?","kind":"boundary"}]}]},{"id":"consistency","name":"Consistency","description":"Dimensions.","findings":[{"id":"consistency-finding","name":"Consistency","description":"Dimensional check.","questions":[{"text":"Are units consistent in the calculation?","kind":"boundary"},{"text":"What checks catch errors?","kind":"action"}]}]}]},{"id":"use","name":"Use","description":"Choosing units.","layers":[{"id":"choice","name":"Choice","description":"Appropriate units.","findings":[{"id":"choice-finding","name":"Choice","description":"Unit choice.","questions":[{"text":"Which unit suits this audience and context?","kind":"action"},{"text":"Is a legal unit required?","kind":"boundary"}]}]},{"id":"machine","name":"Machine-readable","description":"Codes.","findings":[{"id":"machine-finding","name":"Machine","description":"Unit codes.","questions":[{"text":"Which UCUM or QUDT code represents it?","kind":"provenance"},{"text":"Is it used consistently?","kind":"boundary"}]}]}]},{"id":"safety","name":"Safety","description":"Critical errors.","layers":[{"id":"medicine","name":"Medicine","description":"Dose units.","findings":[{"id":"medicine-finding","name":"Medicine","description":"Dose units.","questions":[{"text":"Are dose units clear, avoiding error-prone abbreviations?","kind":"boundary"},{"text":"Which guidance applies?","kind":"provenance"}]}]},{"id":"engineering","name":"Engineering","description":"Design errors.","findings":[{"id":"engineering-finding","name":"Engineering","description":"Engineering checks.","questions":[{"text":"Could a unit error cause a failure here?","kind":"boundary"},{"text":"How is it prevented?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Convert between units using defined factors and state the units used.","Check that values carry the correct units."],"mustNot":["Mix units in calculations without converting them.","Present an obsolete or local unit as standard.","Round or convert doses or loads in a way that changes their safety."],"requiresHuman":["Changing the units used in medical, engineering or legal measurements."]},"ethics":{"considerations":["Unit errors have caused medication overdoses, structural failures and lost spacecraft.","Fair trade depends on honest measures."],"affectedParties":["Patients and users of measured products","Engineers and traders"]},"owners":{"steward":"Nobody: a convention; the international system of units is maintained by the international bureau of weights and measures.","roles":[],"masterSystems":["The International System of Units"]},"relations":[{"target":"Q181175","type":"parent","note":"registry parent class"},{"target":"Q39875001","type":"parent","note":"registry parent class"},{"target":"Q71550118","type":"parent","note":"registry parent class"},{"target":"physical quantity","type":"related","note":"quantity"},{"target":"hand, cup, cable","type":"related","note":"units"},{"target":"SI","type":"related","note":"system"},{"target":"measurement","type":"related","note":"practice"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.unit-of-measurement","Wikidata: Q47574 (https://www.wikidata.org/wiki/Q47574)","UCUM code: code strings machine-readable units","QUDT unit IRI: URI semantic units"]},"properties":{"applicability":"not-applicable","items":[]},"recognition":{"applicability":"optional","items":["Unit symbols and names","Systems: SI, imperial, US customary","Special units such as USP units","Symbols such as m, kg, s, and names on instruments and labels."]},"capabilities":{"applicability":"required","items":["convert between units","check dimensional consistency","choose appropriate units","trace units to definitions"]},"hazards":{"applicability":"required","items":["Unit conversion errors","Missing units","Confusing similar units"]},"interfaces":{"applicability":"required","items":["SI Brochure","ISO 80000","Legal metrology law"]},"context":{"applicability":"required","items":["Making measurements comparable.","SI base and derived units","non-SI units accepted with SI","imperial and US customary units","domain units such as pharmacopoeia units"]}},"sources":[{"title":"Wikidata item Q47574: unit of measurement","url":"https://www.wikidata.org/wiki/Q47574","note":"identity and sense of the item"},{"title":"Wikipedia: Unit of measurement","url":"https://en.wikipedia.org/wiki/Unit_of_measurement","note":"general description of the item"}],"openQuestions":["Should units be instances with UCUM codes?","How should non-SI units be linked?","The registry entry has merged aliases such as look; should they be removed?"],"resources":{"spec":"/models/things/publications/thing-q47574/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q47574/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-11T06:37:34Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-06T19:52:00+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties."},"score":1.0}}