diff --git a/dstat_interface/interface/exp_int.py b/dstat_interface/interface/exp_int.py
index 436b78a42f37ae5222ac0f81325f8bcbcf857e2e..2775dc7acd8dad05320f21bce94d704f863b8d4e 100644
--- a/dstat_interface/interface/exp_int.py
+++ b/dstat_interface/interface/exp_int.py
@@ -213,13 +213,15 @@ class PD(ExpInterface):
         self.entry['sync'] = self.builder.get_object('sync_button')
         self.entry['sync_freq'] = self.builder.get_object('sync_freq')
         self.entry['fft_start'] = self.builder.get_object('fft_entry')
+        self.entry['fft_int'] = self.builder.get_object('fft_int_entry')
         
         self.buttons = map(self.builder.get_object,
                            ['light_button', 'threshold_button'])
                            
         self.shutter_buttons = map(
             self.builder.get_object,
-            ['sync_button', 'sync_freq', 'fft_label', 'fft_entry']
+            ['sync_button', 'sync_freq', 'fft_label', 'fft_entry', 'fft_label2',
+                'fft_int_entry']
             )
         
     def on_light_button_clicked(self, data=None):
@@ -280,6 +282,7 @@ class PD(ExpInterface):
         parameters['sync'] = self.entry['sync'].get_active()
         parameters['sync_freq'] = float(self.entry['sync_freq'].get_text())
         parameters['fft_start'] = float(self.entry['fft_start'].get_text())
+        parameters['fft_int'] = float(self.entry['fft_int'].get_text())
             
         return parameters
         
diff --git a/dstat_interface/interface/pd.glade b/dstat_interface/interface/pd.glade
index 0db0eb27801678372b3b861ec6d978104110e323..bb72ff8153173d2da83cec1bfab0d494fb22372b 100644
--- a/dstat_interface/interface/pd.glade
+++ b/dstat_interface/interface/pd.glade
@@ -340,7 +340,7 @@
                         <property name="max_length">6</property>
                         <property name="invisible_char">●</property>
                         <property name="width_chars">8</property>
-                        <property name="text">0.5</property>
+                        <property name="text">1</property>
                         <property name="xalign">1</property>
                         <property name="invisible_char_set">True</property>
                         <property name="primary_icon_activatable">False</property>
diff --git a/dstat_interface/main.py b/dstat_interface/main.py
index 784444a5fd7787c5c6dee99a2f548e8bb7ab0879..5414032a2e87bb161204111571b2946155529ea2 100755
--- a/dstat_interface/main.py
+++ b/dstat_interface/main.py
@@ -694,6 +694,11 @@ class Main(object):
                         parameters['fft_start'] > parameters['time']-1):
                         raise InputError(parameters['fft_start'],
                                         "FFT must start between 0 and time-1.")
+                    if parameters['fft_int'] < 0:
+                        raise InputError(
+                            parameters['fft_int'],
+                            "Integral bandwidth must be greater than 0"
+                        )
                 
                 self.current_exp = comm.PDExp(parameters)
                 run_experiment()
@@ -863,6 +868,11 @@ class Main(object):
             self.ft_plot.updateline(self.current_exp, 0) 
             self.ft_plot.redraw()
             self.current_exp.data_extra = self.current_exp.ftdata
+            self.statusbar.push(
+                self.message_context_id, " ".join(
+                    ("Integral:",str(self.current_exp.ft_int))
+                    )
+                )
 
         self.databuffer.set_text("")
         self.databuffer.place_cursor(self.databuffer.get_start_iter())
diff --git a/dstat_interface/plot.py b/dstat_interface/plot.py
index c3e846a7fd6e518603045193bdd9b69a8327b5fe..dcd5c8b793d67e28cebfdd3f1f9d031cbaabbc21 100644
--- a/dstat_interface/plot.py
+++ b/dstat_interface/plot.py
@@ -32,14 +32,14 @@ from matplotlib.backends.backend_gtkagg \
 from matplotlib.backends.backend_gtkagg \
     import NavigationToolbar2GTKAgg as NavigationToolbar
     
-from numpy import sin, linspace, pi, mean
+from numpy import sin, linspace, pi, mean, trapz
 from scipy import fft, arange
 from scipy.signal import blackman
 
 def plotSpectrum(y,Fs):
     """
     Plots a Single-Sided Amplitude Spectrum of y(t)
-    """
+    """    
     y = y-mean(y)
     n = len(y) # length of the signal
     k = arange(n)
@@ -50,9 +50,28 @@ def plotSpectrum(y,Fs):
     Y = fft(y*W)/n # fft computing and normalization
     Y = abs(Y[range(n/2)])
     
-    
     return (frq, Y)
 
+def integrateSpectrum(x, y, target, bandwidth):
+    """
+    Returns integral of range of bandwidth centered on target (both in Hz).
+    """
+    j = 0
+    k = len(x)
+    
+    for i in range(len(x)):
+        if x[i] >= target-bandwidth/2:
+            j = i
+            break
+            
+    for i in range(j,len(x)):
+        if x[i] >= target+bandwidth/2:
+            k = i
+            break
+        
+    return trapz(y=y[j:k], x=x[j:k])
+    
+    
 class plotbox(object):
     """Contains main data plot and associated methods."""
     def __init__(self, plotwindow_instance):
@@ -137,9 +156,14 @@ class ft_box(plotbox):
         x = Experiment.data[line_number*2]
         freq = Experiment.parameters['adc_rate_hz']
         i = search_value(x, Experiment.parameters['fft_start'])
-        print i
         
         f, Y = plotSpectrum(y[i:],freq)
+        Experiment.ft_int = integrateSpectrum(
+                                f,
+                                Y,
+                                Experiment.parameters['sync_freq'],
+                                Experiment.parameters['fft_int']
+                                )
         self.lines[line_number].set_ydata(Y)
         self.lines[line_number].set_xdata(f)
         Experiment.ftdata = (f, Y)