diff --git a/tracking/monitors/monitors.py b/tracking/monitors/monitors.py
index 265e57d5b9c84cd213cdf1564d4bd12573521190..01a2e217b660a2c8a2c8d0cf4352a0a72e5bb988 100644
--- a/tracking/monitors/monitors.py
+++ b/tracking/monitors/monitors.py
@@ -615,10 +615,10 @@ class ProfileMonitor(Monitor):
         dict_buffer = {}
         dict_file = {}
         for index, dim in enumerate(self.dimensions):
-            dict_buffer.update({dim : (self.n_bin[index], buffer_size)})
-            dict_buffer.update({dim + "_bin" : (self.n_bin[index] + 1, buffer_size)})
-            dict_file.update({dim : (self.n_bin[index], total_size)})
-            dict_file.update({dim + "_bin" : (self.n_bin[index] + 1, total_size)})
+            dict_buffer.update({dim : (self.n_bin[index] - 1, buffer_size)})
+            dict_buffer.update({dim + "_bin" : (self.n_bin[index] - 1, buffer_size)})
+            dict_file.update({dim : (self.n_bin[index] - 1, total_size)})
+            dict_file.update({dim + "_bin" : (self.n_bin[index] - 1, total_size)})
 
         self.monitor_init(group_name, save_every, buffer_size, total_size,
                           dict_buffer, dict_file, file_name, mpi_mode)
@@ -637,11 +637,9 @@ class ProfileMonitor(Monitor):
 
         self.time[self.buffer_count] = self.track_count
         for index, dim in enumerate(self.dimensions):
-            bins, sorted_index, profile = bunch.binning(dim, self.n_bin[index])
-            bin_array = np.append(np.array(bins.left), bins.right[-1])
-            profile_array = np.array(profile)
-            self.__getattribute__(dim + "_bin")[:, self.buffer_count] = bin_array
-            self.__getattribute__(dim)[:, self.buffer_count] = profile_array
+            bins, sorted_index, profile, center = bunch.binning(dim, self.n_bin[index])
+            self.__getattribute__(dim + "_bin")[:, self.buffer_count] = center
+            self.__getattribute__(dim)[:, self.buffer_count] = profile
         
         self.buffer_count += 1
         
@@ -1044,11 +1042,14 @@ class CavityMonitor(Monitor):
         
         group_name = cavity_name
         dict_buffer = {"cavity_phasor_record":(ring.h, buffer_size,),
-                       "beam_phasor_record":(ring.h, buffer_size,)}
+                       "beam_phasor_record":(ring.h, buffer_size,),
+                       "detune":(buffer_size,)}
         dict_file = {"cavity_phasor_record":(ring.h, total_size,),
-                     "beam_phasor_record":(ring.h, total_size,)}
+                     "beam_phasor_record":(ring.h, total_size,),
+                      "detune":(total_size,)}
         dict_dtype = {"cavity_phasor_record":complex,
-                      "beam_phasor_record":complex}
+                      "beam_phasor_record":complex,
+                      "detune":float}
         
         self.monitor_init(group_name, save_every, buffer_size, total_size,
                           dict_buffer, dict_file, file_name, mpi_mode,