diff --git a/lmwsip.py b/lmwsip.py
index 9fa297b..15ffb2f 100644
--- a/lmwsip.py
+++ b/lmwsip.py
@@ -348,15 +348,46 @@ Logs of
         self.closesocket()
 
 class lmwTimeSerie:
+    """Class for lmw results.
+
+The result are in lmwTimeSerie.ts as array
+
+    [ <time1>, [<value1 a, value1 b, ...], kwaliteit1, additionele kwaliteit1],
+    [ <time2>, [<value2 a, value2 b, ...], kwaliteit2, additionele kwaliteit2],
+    ...
+
+Note:
+    * For most measurements there is only one value (e.g H10).
+    * Additionale kwaliteit is optional and may contain None.
+"""
+
     def __init__(self, start, delta, values):
+        """lmwTimeSerie(start, delta, values)
+
+Create a lmwTimeSerie object with:
+    start:  Start time
+    delta:  Period of the measurements
+    values: lmw result string
+"""
         self.ts = []
         self.addvalues(start, delta, values)
 
     def addvalues(self, start, delta, values):
+        """addvalues(start, delta, values)
+
+Add values to a timeserie
+    start:  Start time
+    delta:  Period of the measurements
+    values: lmw result string
+"""
+        self.ts = []
+
         for e in values.split(";"):
             v = e.split("/")
             v[0] = v[0].split(",")
-            self.ts.append([start, v])
+            if len(v) == 2:
+                v.append(None)
+            self.ts.append([start, v[0], v[1], v[2]])
             start += delta
 
 class sipTimeSeriesError(Exception):