Index: trunk/Mars/mdrs/MHDrsCalibration.cc
===================================================================
--- trunk/Mars/mdrs/MHDrsCalibration.cc	(revision 16110)
+++ trunk/Mars/mdrs/MHDrsCalibration.cc	(revision 16891)
@@ -359,2 +359,27 @@
     MHCamEvent::Paint(o);
 }
+
+Short_t MHDrsCalibration::GetNumUnderflows(float lvl) const
+{
+    if (!fResult)
+        return -1;
+
+    short cnt = 0;
+
+    for (int drs=0; drs<160; drs++)
+    {
+        const int p = drs*9*1024;
+
+        double avg = 0;
+        for (int i=0; i<1024*9; i++)
+            avg += fResult->fOffset[p+i];
+
+        avg /= 1024*9*fResult->fNumOffset;
+
+        if (avg/1000<lvl)
+            cnt++;
+    }
+
+    return cnt;
+
+}
Index: trunk/Mars/mdrs/MHDrsCalibration.h
===================================================================
--- trunk/Mars/mdrs/MHDrsCalibration.h	(revision 16110)
+++ trunk/Mars/mdrs/MHDrsCalibration.h	(revision 16891)
@@ -63,4 +63,6 @@
     void Paint(Option_t *o="");
 
+    Short_t GetNumUnderflows(float lvl) const;
+
     ClassDef(MHDrsCalibration, 1) // A list of histograms storing the Fadc spektrum of one pixel
 };