diff --git a/Scripts/MaCFP-4/Cone_analysis.py b/Scripts/MaCFP-4/Cone_analysis.py
index 0c12c80..40f0490 100644
--- a/Scripts/MaCFP-4/Cone_analysis.py
+++ b/Scripts/MaCFP-4/Cone_analysis.py
@@ -148,6 +148,8 @@ def Calculate_dm_dt(df:pd.DataFrame):
     """Calculate mass loss rate ."""
     dt = df['Time (s)'].shift(-2) - df['Time (s)'].shift(2)
     df['dm/dt'] = (df['Mass (g)'].shift(2) - df['Mass (g)'].shift(-2)) / dt
+    df['dm/dt'] = df['dm/dt'].interpolate(method='linear', limit_direction='both') #avoid nan_values
+    print(df)
     return df