diff --git a/pPro.ttl b/pPro.ttl
index f1302408dae82a82c29b4e42e3dcf1228749189d..a29a8df5a4e155ce04ac8022052772745af40bd5 100644
--- a/pPro.ttl
+++ b/pPro.ttl
@@ -1,5 +1,4 @@
 # baseURI: http://www.foodvoc.org/resource/pPro/
-# imports: http://datashapes.org/dash
 # imports: http://www.ontology-of-units-of-measure.org/resource/om-2/
 # imports: http://www.w3.org/2004/02/skos/core
 # prefix: ppro
@@ -8,17 +7,16 @@
 @prefix MathM: <http://www.w3.org/1998/Math/MathML> .
 @prefix om: <http://www.ontology-of-units-of-measure.org/resource/om-2/> .
 @prefix owl: <http://www.w3.org/2002/07/owl#> .
-@prefix p1: <http://example.org/file1#> .
 @prefix ppro: <http://www.foodvoc.org/resource/pPro/> .
 @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
 @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
 @prefix sh: <http://www.w3.org/ns/shacl#> .
 @prefix skos: <http://www.w3.org/2004/02/skos/core#> .
+@prefix sosa: <http://www.w3.org/ns/sosa/> .
 @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
 
 ppro:
   a owl:Ontology ;
-  owl:imports <http://datashapes.org/dash> ;
   owl:imports om: ;
   owl:imports <http://www.w3.org/2004/02/skos/core> ;
 .
@@ -783,6 +781,13 @@ ppro:hasMaterialType
   rdfs:range ppro:MaterialType ;
   skos:prefLabel "has material type" ;
 .
+ppro:hasMeasurement
+  a owl:ObjectProperty ;
+  rdfs:domain om:Quantity ;
+  rdfs:label "has measurement" ;
+  rdfs:range ppro:Measurement ;
+  skos:prefLabel "has measurement" ;
+.
 ppro:hasMethod
   a owl:ObjectProperty ;
   rdfs:domain ppro:ProcessingStep ;
@@ -824,6 +829,13 @@ ppro:hasPH
   rdfs:range om:Acidity ;
   skos:prefLabel "has pH" ;
 .
+ppro:hasProcessingStep
+  a owl:ObjectProperty ;
+  rdfs:domain ppro:Measurement ;
+  rdfs:label "has processing step" ;
+  rdfs:range ppro:ProcessingStep ;
+  skos:prefLabel "has processing step" ;
+.
 ppro:hasRecommendedDIAASValue0-6months
   a owl:ObjectProperty ;
   rdfs:domain ppro:AminoAcid ;
@@ -1025,15 +1037,6 @@ ppro:oxidation
 ppro:pHrule
   a sh:NodeShape ;
   skos:prefLabel "pHrule" ;
-  sh:property [
-      a sh:PropertyShape ;
-      sh:path ppro:hasPH ;
-      sh:datatype xsd:decimal ;
-      sh:maxInclusive "14"^^xsd:decimal ;
-      sh:minInclusive "0"^^xsd:decimal ;
-      sh:name "has PH" ;
-    ] ;
-  sh:targetClass owl:Thing ;
 .
 ppro:pea
   a ppro:SensoryCategory ;
@@ -1200,3 +1203,34 @@ ppro:valine
 skos:note
   rdfs:range xsd:string ;
 .
+sosa:Sensor
+  a owl:Class ;
+  a sh:NodeShape ;
+  rdfs:comment "Device, agent (including humans), or software (simulation) involved in, or implementing, a Procedure. Sensors respond to a stimulus, e.g., a change in the environment, or input data composed from the results of prior Observations, and generate a Result. Sensors can be hosted by Platforms."@en ;
+  rdfs:label "Sensor"@en ;
+  rdfs:subClassOf owl:Thing ;
+  skos:definition "Device, agent (including humans), or software (simulation) involved in, or implementing, a Procedure. Sensors respond to a stimulus, e.g., a change in the environment, or input data composed from the results of prior Observations, and generate a Result. Sensors can be hosted by Platforms."@en ;
+  skos:example "Accelerometers, gyroscopes, barometers, magnetometers, and so forth are Sensors that are typically mounted on a modern smart phone (which acts as Platform). Other examples of sensors include the human eyes."@en ;
+  skos:prefLabel "Sensor" ;
+.
+sosa:isObservedBy
+  a owl:ObjectProperty ;
+  rdfs:comment "Relation between an ObservableProperty and the Sensor able to observe it."@en ;
+  rdfs:domain om:Quantity ;
+  rdfs:label "is observed by"@en ;
+  rdfs:range sosa:Sensor ;
+  skos:definition "Relation between an ObservableProperty and the Sensor able to observe it."@en ;
+  skos:prefLabel "is observed by"@en ;
+.
+sosa:madeBySensor
+  a owl:ObjectProperty ;
+  rdfs:comment "Relation between an Observation and the Sensor which made the Observation."@en ;
+  rdfs:domain ppro:Measurement ;
+  rdfs:label "made by sensor"@en ;
+  rdfs:range sosa:Sensor ;
+  skos:definition "Relation between an Observation and the Sensor which made the Observation."@en ;
+  skos:prefLabel "made by sensor" ;
+.
+[
+  a sh:PropertyShape ;
+].