diff --git a/src/icartt/dataset.py b/src/icartt/dataset.py
index 41d47faf33c1b98766364a9e4c3ce6c5e05797f0..b00c338b16c52a58ec56c05dca645a45955b4a3e 100644
--- a/src/icartt/dataset.py
+++ b/src/icartt/dataset.py
@@ -25,9 +25,10 @@ class VariableType(IntEnum):
     DependentVariable = 4
 
 
-def sanitize(val, miss):
-    # TODO: should not use == for float comparison instead, use np.isclose
-    return float(val) if not float(val) == float(miss) else np.NaN
+def vmiss_to_npnan(val, miss):
+    """converts value to np.nan if is (almost) equal to miss"""
+    val, miss = map(float, (val, miss))
+    return np.NaN if np.isclose(val, miss) else val
 
 
 class DataStore1001:
@@ -63,12 +64,12 @@ class DataStore1001:
         if not self.ivarname in kwargs.keys():
             raise Exception("Need independent variable data.")
 
-        ivarvalue = sanitize(kwargs[self.ivarname], self.missvals[self.ivarname])
+        ivarvalue = vmiss_to_npnan(kwargs[self.ivarname], self.missvals[self.ivarname])
 
         newline = np.array(np.NaN, dtype=[(v, "f8") for v in self.varnames])
         for key in kwargs.keys():
             if key in self.varnames:
-                newline[key] = sanitize(kwargs[key], self.missvals[key])
+                newline[key] = vmiss_to_npnan(kwargs[key], self.missvals[key])
 
         if type(self.data) is type(None): # TODO: None is the sole instance of None ;-) => can use "if self.data is None"
             self.data = newline
@@ -141,7 +142,7 @@ class DataStore2110(collections.UserDict):
     def _addBulk(self, raw, n):
         cur = 0
         while cur < n:
-            ivarvalue = sanitize(raw[cur][0], self.missvals[self.ivarname])
+            ivarvalue = vmiss_to_npnan(raw[cur][0], self.missvals[self.ivarname])
 
             self._addAuxline(raw[cur])
             cur += 1
@@ -159,7 +160,7 @@ class DataStore2110(collections.UserDict):
         if not self.ivarname in kwargs.keys():
             raise Exception("Need independent variable data.")
 
-        ivarvalue = sanitize(kwargs[self.ivarname], self.missvals[self.ivarname])
+        ivarvalue = vmiss_to_npnan(kwargs[self.ivarname], self.missvals[self.ivarname])
 
         # this is an AUX line
         if any([x in self.auxvarnames for x in kwargs.keys()]): # TODO: any (all as well) do not require a comprehension; pure generator expression works fine