diff --git a/ontology/saref4auto.ttl b/ontology/saref4auto.ttl
index e1397c47f8b9bf6733b1091666f9ffbba8199b82..e83403496bc24d510ce7fb97b9f581e254fc5de7 100644
--- a/ontology/saref4auto.ttl
+++ b/ontology/saref4auto.ttl
@@ -151,11 +151,11 @@ saref:isControlledByDevice rdf:type owl:ObjectProperty ;
                            rdfs:label "is controlled by device"@en .
 
 
-###  https://saref.etsi.org/core/isMeasuredByDevice
-saref:isMeasuredByDevice rdf:type owl:ObjectProperty ;
-                         rdfs:comment "A relationship specifying the devices that can measure a certain property"@en ;
-                         rdfs:isDefinedBy saref: ;
-                         rdfs:label "is measured by device"@en .
+saref:isObservedBy a owl:ObjectProperty ;
+    rdfs:subPropertyOf saref:isActedUponBy ;
+    owl:inverseOf saref:observes ;
+    rdfs:label "is observed by"@en ;
+    rdfs:comment "Links a feature, property, or state, to the device, function, command, or procedure execution, that observes it."@en .
 
 
 ###  https://saref.etsi.org/core/isMeasuredIn
@@ -829,7 +829,7 @@ saref:Property rdf:type owl:Class ;
                                  owl:allValuesFrom saref:Device
                                ] ,
                                [ rdf:type owl:Restriction ;
-                                 owl:onProperty saref:isMeasuredByDevice ;
+                                 owl:onProperty saref:isObservedBy ;
                                  owl:allValuesFrom saref:Device
                                ] ,
                                [ rdf:type owl:Restriction ;