diff --git a/src/SimNDT/run_setup/snapshots.py b/src/SimNDT/run_setup/snapshots.py
index 8da2f73..7564de8 100644
--- a/src/SimNDT/run_setup/snapshots.py
+++ b/src/SimNDT/run_setup/snapshots.py
@@ -52,6 +52,7 @@ class SnapShots:
         self.volF = []
         self.volS = []
         self.volP = []
+        self.vecT = [] # time vector
 
         print("SnapShots Field="+str(Field)+" enableNumPy="+str(enableNumPy)+" enableCsv="+str(enableCsv)+" enableVolume="+str(enableVolume)+ " enableSignals="+str(enableSignals)+ " enableMaterial="+str(enableMaterial))
         # if self.File_path does not exist, create it
@@ -127,12 +128,18 @@ class SnapShots:
           np.save(FILE_PATH,VT)
 
         
-    def save_signal(self, D , n, Label):
+    def save_signal(self, D , n, Label, dt):
     
         self.Label = Label       
         xn = D.shape[1]
         yn = D.shape[0]
-        print('['+str(int(n / self.Step))+'] Saving signal '+Label+' shape=('+str(xn)+','+str(yn)+') sensorShape='+str(self.sensorShape))
+        if self.enableVolume:
+          print('['+str(int(n / self.Step))+'@'+str(dt*n)+'] Storing signal '+Label+' field shape=('+str(xn)+','+str(yn)+')'+
+                ' sensorShape='+str(self.sensorShape))
+        else:
+          print('['+str(int(n / self.Step))+'@'+str(dt*n)+'] Saving signal '+Label+' field shape=('+str(xn)+','+str(yn)+')'+
+                ' sensorShape='+str(self.sensorShape))
+        
         dx = 1 # sensor delta
         dy = 1
         ox = 0 # offset
@@ -156,9 +163,10 @@ class SnapShots:
               S[y,x]=D[oy+y*dy,ox+x*dx]
         else:
           S = D 
-
+        
         if self.enableVolume:
           self.volS.append(np.copy(S))
+          self.vecT.append(dt*n)
         elif self.enableNumPy:
           FILE = self.Filename + ("-signal-"+Label+"-%05d" % (int(n / self.Step)))
           FILE_PATH = os.path.join(self.File_path, FILE)
@@ -252,12 +260,18 @@ class SnapShots:
             FILE = self.Filename + '-signal-'+self.Label+".csv"
             FILE_PATH = os.path.join(self.File_path, FILE)
             vol=np.array(self.volS)
+            vec=np.array(self.vecT)
+            vec=vec.reshape(vec.shape[0],1)
             if vol.shape[1]==1:
               vol=vol.reshape(vol.shape[0],vol.shape[1])
             elif vol.shape[2]==1:
               vol=vol.reshape(vol.shape[0],vol.shape[2])
+            vol=np.hstack((vec,vol))
             print("Saving reduced CSV S-volume "+str(vol.shape)+" in "+FILE_PATH)
-            np.savetxt(FILE_PATH, vol, delimiter=",")
+            header="time"
+            for i in range(1,vol.shape[1]):
+              header=header+",sig"+str(i)
+            np.savetxt(FILE_PATH, vol, delimiter=",",header=header,comments="")
             self.volS=[]
 
         if len(self.volP) > 0: