diff --git a/sampling.ttl b/sampling.ttl
index a068b58..3303b75 100644
--- a/sampling.ttl
+++ b/sampling.ttl
@@ -156,7 +156,7 @@
                                 emobon-core:Observatory
                             ) ; 
                         ] ;
-    rdfs:range          xsd:nonNegativeInteger ;
+    rdfs:range          qudt:QuantityValue ;
 .
 
 <{{baseuri}}/{{name}}#originCountry>