diff --git a/ontology/saref.ttl b/ontology/saref.ttl
index 9e304185f2355d392ea0eacf8eda30144bce9638..0d9d78e682a4dc14d5ef5cbfd0e72798f7766a9a 100644
--- a/ontology/saref.ttl
+++ b/ontology/saref.ttl
@@ -451,9 +451,10 @@ saref:Appliance a owl:Class ;
 
 saref:Sensor a owl:Class ;
     rdfs:subClassOf saref:Device ;
-    rdfs:comment "A device designed to observe one or more properties or states of one or more features of interest."@en ;
+    rdfs:comment "A device designed to observe and measure one or more properties or states of one or more features of interest."@en ;
     rdfs:label "Sensor"@en ;
     rdfs:subClassOf [ a owl:Restriction ; owl:onProperty saref:observes ; owl:minCardinality 1 ] ;
+    skos:historyNote "V4.1.1: Definition of Sensor and Meter are updated to better distinguish one from the other."@en ;
     skos:historyNote "V3.2.1: Definition of Sensor is simplified and grounded on saref:observes. Local restriction on saref:hasFunction is deleted."@en .
 
 saref:Actuator a owl:Class ;
@@ -469,6 +470,7 @@ saref:Meter a owl:Class ;
     rdfs:comment "A device designed to observe and additionally do some computation and/or display one or more properties of one or more features of interest."@en ;
     rdfs:label "Meter"@en ;
     rdfs:subClassOf [ a owl:Restriction ; owl:onProperty saref:observes ; owl:minCardinality 1 ] ;
+    skos:historyNote "V4.1.1: Definition of Sensor and Meter are updated to better distinguish one from the other."@en ;
     skos:historyNote "V3.2.1: Definition of Meter is simplified and grounded on saref:observes. Local restriction on saref:hasFunction is deleted."@en .