diff --git a/lib/raweat.hpp b/lib/raweat.hpp
index 684b036..b460719 100644
--- a/lib/raweat.hpp
+++ b/lib/raweat.hpp
@@ -511,7 +511,14 @@ public:
   {
     // assert ( segments_.size() > 0 );
 
-    return valid_ ? segments_["punit marker"][7] : std::string("None");
+    if ( datasec_["punit"].size() > 0 )
+    {
+      return valid_ ? segments_["punit marker"][7] : std::string("None");
+    }
+    else
+    {
+      return std::string("None");
+    }
   }
 
   // get time offset
diff --git a/pyt/example.py b/pyt/example.py
index c3b7e4e..bbfe5b8 100644
--- a/pyt/example.py
+++ b/pyt/example.py
@@ -1,7 +1,7 @@
 
 import raw_eater
 
-eatraw = raw_eater.raweater(b"sample/pressure_Vacuum.raw")
+eatraw = raw_eater.raweater(b"sample/Rangerover_Evoque_F-RR534_2019-05-07/ABS_A_Port1.raw")
 # eatraw = raw_eater.raweater(b"/home/mario/Downloads/FAMOS_Datenformat_ab61.pdf")
 
 print(str(eatraw.validity()))