exported
equivalent
indicator
IRI:
http://www.inf.ufrgs.br/ontologies/copi#Indicator
Generated on 2026-04-15
Natural Language Definition
EN
An indicator is an instrument that displays or shows the value or status of a measured variable or condition to make it perceptible to operators.
PT-BR
Um indicador é um instrumento que exibe ou mostra o valor ou status de uma variável medida ou condição para torná-la perceptível aos operadores.
Formal Axioms
Semi-formal (Aristotelian)
Every indicator is an instrument that bears an indication function to display process information in human-perceptible form.
First-Order Logic Theory
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▸ Stored override
∀x(Indicator(x) ↔ (Instrument(x) ∧ ∃f(IndicationFunction(f) ∧ bearerOf(x,f))))
OWL 2 / Turtle
@prefix copi: <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix : <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix bfo: <http://purl.obolibrary.org/obo/> .
@prefix iof-core: <https://spec.industrialontologies.org/ontology/construct/> .
@prefix iof-av: <https://spec.industrialontologies.org/ontology/annotation/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix qudt: <http://qudt.org/schema/qudt/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix apv: <http://inf.ufrgs.br/ontologies/apv#> .
### COPI — Core Ontology for Petroleum Installations
### Class module: Indicator
<https://www.inf.ufrgs.br/ontologies/copi>
rdf:type owl:Ontology ;
dcterms:title "Core Ontology for Petroleum Installations (COPI)"@en ;
dcterms:title "Ontologia Core para Instalações de Petróleo (COPI)"@pt-br ;
dcterms:description "BFO/IOF-Core conformant ontology of equipment classes for petroleum production plants, developed using the five-step RDL enrichment method."@en ;
skos:scopeNote "Material artifacts (bfo:material_entity) that (i) are part of a petroleum production plant, and (ii) bear at least one function whose realization involves the transport (e.g. production and injection), processing (separation and other processes), control, monitoring, measurement, containment or offloading of material or energy."@en ;
skos:scopeNote "Artefatos materiais (bfo:material_entity) que (i) fazem parte de uma planta de produção de petróleo, e (ii) possuem ao menos uma função cuja realização envolve o transporte (p. ex. produção e injeção), processamento (separação e outros processos), controle, monitoramento, medição, contenção ou escoamento de material ou energia."@pt-br ;
skos:scopeNote "COPI provides high-level equipment categories defined by function to demonstrate the defined-class mechanism. Equipment subtypes are annotated with references to CFIHOS and PCA RDL terms. COPI is not a reference data library; organizations should use CFIHOS, PCA RDL, or ISO 14224 for comprehensive equipment classification."@en ;
skos:scopeNote "COPI fornece categorias de alto nível de equipamentos definidas por função para demonstrar o mecanismo de classe definida. Os subtipos de equipamentos são anotados com referências aos termos do CFIHOS e do PCA RDL. COPI não é uma biblioteca de dados de referência; organizações devem utilizar o CFIHOS, o PCA RDL ou a ISO 14224 para classificação abrangente de equipamentos."@pt-br ;
owl:versionInfo "1.1.0" ;
owl:imports <https://spec.industrialontologies.org/ontology/core/Core/> ;
owl:imports <http://purl.obolibrary.org/obo/bfo/2020/bfo.owl> ;
dcterms:creator "Nicolau Oyhenard dos Santos"@en ;
dcterms:contributor "Cauã Antunes" ;
dcterms:contributor "Haroldo Rojas" ;
dcterms:contributor "Rafael Petry" ;
dcterms:contributor "Régis Romeu" ;
dcterms:contributor "Mara Abel" ;
dcterms:isPartOf <https://inf.ufrgs.br/projetos/OntoKG> ;
dcterms:publisher "Universidade Federal do Rio Grande do Sul (UFRGS)"@en ;
dcterms:license <https://creativecommons.org/licenses/by/4.0/> ;
dcterms:created "2026-04-08"^^xsd:date ;
dcterms:modified "2026-10-07"^^xsd:date ;
apv:GlobalMinLanguageCoverage "en pt-br" ;
apv:ClassURIFormationRule "https://www[.]inf[.]ufrgs[.]br/ontologies/copi/(COPI_[0-9]{7}|[A-Z][A-Za-z0-9]*)" ;
apv:ClassMinAnnotationCoverage "rdfs:label https://spec.industrialontologies.org/ontology/annotation/naturalLanguageDefinition" .
iof-av:naturalLanguageDefinition rdf:type owl:AnnotationProperty ;
apv:MinAnnotationLength 20 .
### Identity-giving function
:COPI_0000028 rdf:type owl:Class ; # IndicationFunction
rdfs:subClassOf :COPI_0000029 ; # InstrumentationFunction
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:allValuesFrom :COPI_0000552 # IndicationProcess
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:someValuesFrom :COPI_0000552 # IndicationProcess
] ;
rdfs:label "indication function"@en ;
rdfs:label "função de indicação"@pt-br .
:COPI_0000029 rdf:type owl:Class . # InstrumentationFunction
### Process type
:COPI_0000552 rdf:type owl:Class ; # IndicationProcess
rdfs:subClassOf iof-core:MeasurementProcess ;
rdfs:label "indication process"@en ;
rdfs:label "processo de indicação"@pt-br .
iof-core:MeasurementProcess rdf:type owl:Class .
:COPI_0000552 # IndicationProcess
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasInput ;
owl:someValuesFrom iof-core:InformationContentEntity
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasSpecifiedOutput ;
owl:someValuesFrom :COPI_0000046 # VisualIndication
] .
### Equipment universal: Indicator
:COPI_0000127 rdf:type owl:Class ; # Indicator
owl:equivalentClass [
rdf:type owl:Class ;
owl:intersectionOf (
:COPI_0000091 # Instrument
[
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasFunction ; # Object branch (MaterialArtifact/Assembly/Object/FiatObjectPart)
owl:someValuesFrom :COPI_0000028 # IndicationFunction
]
)
] ;
rdfs:label "indicator"@en ;
rdfs:label "indicador"@pt-br ;
iof-av:naturalLanguageDefinition "An indicator is an instrument that displays or shows the value or status of a measured variable or condition to make it perceptible to operators."@en ;
skos:definition "An indicator is an instrument that displays or shows the value or status of a measured variable or condition to make it perceptible to operators."@en ;
iof-av:naturalLanguageDefinition "Um indicador é um instrumento que exibe ou mostra o valor ou status de uma variável medida ou condição para torná-la perceptível aos operadores."@pt-br ;
iof-av:semiFormalNaturalLanguageAxiom "Every indicator is an instrument that bears an indication function to display process information in human-perceptible form."@en ;
iof-av:firstOrderLogicAxiom "∀x(Indicator(x) ↔ (Instrument(x) ∧ ∃f(IndicationFunction(f) ∧ bearerOf(x,f))))"@en ;
skos:definition "[ISO 15926-4] An <INDICATOR> is an <INSTRUMENTATION FUNCTION> that has a capability of <INDICATING>"@en ;
skos:definition "[SLB Glossary] A visible sign of a chemical reaction."@en ;
skos:definition "[OnePetro] In a chemical context, an indicator is a chemical in a titration reaction that changes color at a certain pH. In the context of a mechanical load, an indicator is a dial or gauge."@en ;
skos:definition "[POSC Caesar] An artefact that is a intended to display the value or the status of a condition."@en .
# Disjointness: Indicator and Transmitter
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000127 :COPI_0000157 ) . # Indicator, Transmitter
# Disjointness: Indicator and Controller
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000127 :COPI_0000234 ) . # Indicator, Controller
# Disjointness: Indicator and Actuator
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000127 :COPI_0000207 ) . # Indicator, Actuator
Axiomatization Decision Log
1
Identity-Giving Function
Function class
IndicationFunction
⊑ InstrumentationFunction
Realized in
IndicationProcess
⊑ MeasurementProcess
The identity-giving function is the capability to make information visible or perceptible to operators - converting process variables, conditions, or states into human-readable form. This unifies all indicator types from mechanical gauges to digital displays to chemical color changes.
✓
Expert review — Accepted
2
Genus Determination
Instrument
From the parent_candidates, both INSTRUMENTATION FUNCTION and Instrumentation And Control Equipment suggest an instrumentation context. The enriched classes show many indicators as subtypes of 'Instrument' (flow indicator, limit switch, transmitter all use Instrument as genus). Instrument is the most specific appropriate superclass that captures the measurement/indication domain, though it is not yet enriched in our system.
✓
Expert review — Accepted
3
Necessary Parts
No necessary parts recorded (concept may be primitive at this level).
The only universal necessary part is some form of Display component that makes the indicated information perceptible to operators. Other parts (sensing elements, signal conditioning, housings) vary significantly across subtypes and implementation methods.
✓
Expert review — Accepted
4
Process Participation Signature ⟨I, O, T⟩
Inputs (I)
InformationContentEntity
— measurand or process variable
Outputs (O)
VisualIndication
— human-perceptible display
Transformation (T)
information conversion from measurement signal to human-readable display
Indicators transform process information (electrical signals, physical properties, chemical states) into human-perceptible visual displays. The signature is broad to accommodate diverse implementations from mechanical gauges to digital displays to chemical color changes.
✓
Expert review — Accepted
5
Axiom Mode Decision
Necessary + Sufficient
— modelled as a defined class
(≡, EquivalentClass). Automatic classification is
appropriate for this concept.
✓
Expert review — Accepted
Disjointness Axioms
Transmitter
Controller
Actuator
C2: Transmitter, Controller. C4: Actuator. Indicators display information locally while transmitters send signals remotely; controllers manipulate process variables while indicators only display; actuators perform physical actions while indicators only show information. These represent incompatible process participation signatures.
Cross-Standard Observations
ISO15926 defines indicator as an instrumentation function, while POSC Caesar and OnePetro treat it as an artifact/device. The SLB definition focuses specifically on chemical indicators. This analysis treats it as the artifact that bears the indication function, consistent with the material entity focus of equipment ontologies.
