diff --git a/common/python/nomadcore/caching_backend.py b/common/python/nomadcore/caching_backend.py
index e0f85954ebba20f155d5cfd8c0f602ad8843f928..acf7f94c3bb5adbf47cdbe12b460c9f5ddede884 100644
--- a/common/python/nomadcore/caching_backend.py
+++ b/common/python/nomadcore/caching_backend.py
@@ -398,7 +398,8 @@ class ActiveBackend(object):
     def addValue(self, metaName, value, gIndex = -1):
         """adds a json value corresponding to metaName
         the value is added to the section the meta info metaName is in
-        a gIndex of -1 means the latest section"""
+        a gIndex of -1 means the latest section
+        """
         dataManager = self.dataManagers[metaName]
         cachingLevel = dataManager.cachingLevel
         if cachingLevel == CachingLevel.Forward or cachingLevel == CachingLevel.ForwardAndCache or cachingLevel == CachingLevel.PreOpenedCache:
@@ -412,15 +413,16 @@ class ActiveBackend(object):
         added to the section the meta info metaName is in A gIndex of -1 means
         the latest section.
         """
-        value = self.convert_unit(metaName, value, unit)
+        if unit is not None:
+            value = self.convert_unit(metaName, value, unit)
 
         dataManager = self.dataManagers[metaName]
         cachingLevel = dataManager.cachingLevel
         if cachingLevel == CachingLevel.Forward or cachingLevel == CachingLevel.ForwardAndCache or cachingLevel == CachingLevel.PreOpenedCache:
             if self.superBackend:
                 self.superBackend.addRealValue(metaName, value, gIndex)
-        if cachingLevel == CachingLevel.ForwardAndCache or cachingLevel == CachingLevel.Cache or cachingLevel == CachingLevel.PreOpenedCache:
-            dataManager.superSectionManager.addRealValue(dataManager.metaInfo, value, gIndex)
+        if cachingLevel == CachingLevel.ForwardAndCache or cachingLevel == CachingLevel.Cache:
+            dataManager.superSectionManager.addValue(dataManager.metaInfo, value, gIndex)
 
     def addArray(self, metaName, shape, gIndex = -1):
         """adds a new array value of the given size corresponding to metaName
@@ -438,7 +440,8 @@ class ActiveBackend(object):
     def setArrayValues(self, metaName, values, offset = None, gIndex = -1, unit=None):
         """Adds values to the last array added, array must be a numpy array
         """
-        values = self.convert_unit(metaName, values, unit)
+        if unit is not None:
+            values = self.convert_unit(metaName, values, unit)
 
         dataManager = self.dataManagers[metaName]
         cachingLevel = dataManager.cachingLevel
@@ -452,7 +455,9 @@ class ActiveBackend(object):
         """Adds an array value with the given array values.  Values must be a
         numpy array.
         """
-        values = self.convert_unit(metaName, values, unit)
+        if unit is not None:
+            values = self.convert_unit(metaName, values, unit)
+
         dataManager = self.dataManagers[metaName]
         cachingLevel = dataManager.cachingLevel
         if cachingLevel == CachingLevel.Forward or cachingLevel == CachingLevel.ForwardAndCache or cachingLevel == CachingLevel.PreOpenedCache:
@@ -476,9 +481,6 @@ class ActiveBackend(object):
     def convert_unit(self, metaName, value, unit):
         """Try to perform a unit conversion.
         """
-        if unit is None:
-            return value
-
         # If a unit has been specified in the metainfo, check that the
         # conversion can be done
         metaInfo = self.metaInfoEnv().infoKindEl(metaName)
diff --git a/common/python/nomadcore/csvparsing.py b/common/python/nomadcore/csvparsing.py
index 4d5e515afe1242477e838ea8b2e495d565b25fbb..ca9e158c3a9f6fcde328b3a59422bafbf880d4f4 100644
--- a/common/python/nomadcore/csvparsing.py
+++ b/common/python/nomadcore/csvparsing.py
@@ -5,7 +5,7 @@ logger = logging.getLogger(__name__)
 
 
 #===============================================================================
-def iread(filepath, columns, delimiter=r"\s+", comments=r"#", start=None, end=None, n_conf=None):
+def iread(filepath, columns=None, delimiter=r"\s+", comments=r"#", start=None, end=None, n_conf=None):
     """Used to iterate a CSV-like file. If a separator is provided the file
     is iterated one configuration at a time. Only keeps one configuration
     of the file in memory. If no separator is given, the whole file will be
@@ -164,6 +164,6 @@ def iread(filepath, columns, delimiter=r"\s+", comments=r"#", start=None, end=No
                     conf.append(line_values)
                     i_line += 1
                     if i_line == n_conf:
-                        yield conf
+                        yield np.array(conf)
                         conf = []
                         i_line = 0
diff --git a/common/python/nomadcore/local_backend.py b/common/python/nomadcore/local_backend.py
index 17ef6e6e6ae418effedb3b18ee05d4030e2549c0..2a7e54eba73210be90d6847d8476601e45022b50 100644
--- a/common/python/nomadcore/local_backend.py
+++ b/common/python/nomadcore/local_backend.py
@@ -103,6 +103,9 @@ class LocalBackend(object):
 
         dataManager.superSectionManager.addValue(dataManager.metaInfo, value, gIndex)
 
+    def addRealValue(self, metaName, value, gIndex=-1):
+        self.addValue(metaName, value, gIndex)
+
     def addArrayValues(self, metaName, values, gIndex=-1):
 
         dataManager = self.dataManagers[metaName]