diff --git a/FDTD/operator.cpp b/FDTD/operator.cpp
index 2156ab4..f1b7090 100644
--- a/FDTD/operator.cpp
+++ b/FDTD/operator.cpp
@@ -1064,14 +1064,14 @@ bool Operator::CalcPEC()
 {
 	m_Nr_PEC[0]=0;	m_Nr_PEC[1]=0;	m_Nr_PEC[2]=0;
 
-	CalcPEC_Range(0,numLines[0]-1);
+	CalcPEC_Range(0,numLines[0]-1,m_Nr_PEC);
 
 	CalcPEC_Curves();
 
 	return true;
 }
 
-void Operator::CalcPEC_Range(unsigned int startX, unsigned int stopX)
+void Operator::CalcPEC_Range(unsigned int startX, unsigned int stopX, unsigned int* counter)
 {
 	double coord[3];
 	double delta;
@@ -1087,7 +1087,6 @@ void Operator::CalcPEC_Range(unsigned int startX, unsigned int stopX)
 					coord[0] = discLines[0][pos[0]];
 					coord[1] = discLines[1][pos[1]];
 					coord[2] = discLines[2][pos[2]];
-					MainOp->SetPos(pos[0],pos[1],pos[2]);
 					delta=MainOp->GetIndexDelta(n,pos[n]);
 					coord[n]= discLines[n][pos[n]] + delta*0.5;
 					CSProperties* prop = CSX->GetPropertyByCoordPriority(coord, (CSProperties::PropertyType)(CSProperties::MATERIAL | CSProperties::METAL));
@@ -1097,7 +1096,7 @@ void Operator::CalcPEC_Range(unsigned int startX, unsigned int stopX)
 						{
 							GetVV(n,pos[0],pos[1],pos[2]) = 0;
 							GetVI(n,pos[0],pos[1],pos[2]) = 0;
-							++m_Nr_PEC[n];
+							++counter[n];
 				//							cerr << "CartOperator::CalcPEC: PEC found at " << pos[0] << " ; "  << pos[1] << " ; " << pos[2] << endl;
 						}
 					}
diff --git a/FDTD/operator.h b/FDTD/operator.h
index 8b5cddd..99fa4d6 100644
--- a/FDTD/operator.h
+++ b/FDTD/operator.h
@@ -106,8 +106,9 @@ protected:
 	//! Calculate the field excitations.
 	virtual bool CalcFieldExcitation();
 
+	unsigned int m_Nr_PEC[3]; //count PEC edges
 	virtual bool CalcPEC();
-	virtual void CalcPEC_Range(unsigned int startX, unsigned int stopX);	//internal to CalcPEC
+	virtual void CalcPEC_Range(unsigned int startX, unsigned int stopX, unsigned int* counter);	//internal to CalcPEC
 	virtual void CalcPEC_Curves();	//internal to CalcPEC
 
 	//Calc timestep only internal use
@@ -127,8 +128,6 @@ protected:
 	double* EC_L[3];
 	double* EC_R[3];
 
-	unsigned int m_Nr_PEC[3];
-
 	int m_MeshType;
 	unsigned int numLines[3];
 	double* discLines[3];
diff --git a/FDTD/operator_multithread.cpp b/FDTD/operator_multithread.cpp
index 6acecba..1b8daff 100644
--- a/FDTD/operator_multithread.cpp
+++ b/FDTD/operator_multithread.cpp
@@ -46,6 +46,9 @@ Operator_Multithread::Operator_Multithread()
 {
 	m_CalcEC_Start=NULL;
 	m_CalcEC_Stop=NULL;
+
+	m_CalcPEC_Start=NULL;
+	m_CalcPEC_Stop=NULL;
 }
 
 void Operator_Multithread::Init()
@@ -53,6 +56,9 @@ void Operator_Multithread::Init()
 	Operator_SSE_Compressed::Init();
 	m_CalcEC_Start=NULL;
 	m_CalcEC_Stop=NULL;
+
+	m_CalcPEC_Start=NULL;
+	m_CalcPEC_Stop=NULL;
 }
 
 void Operator_Multithread::Reset()
@@ -63,6 +69,9 @@ void Operator_Multithread::Reset()
 
 	delete m_CalcEC_Start;m_CalcEC_Start=NULL;
 	delete m_CalcEC_Stop;m_CalcEC_Stop=NULL;
+
+	delete m_CalcPEC_Start;m_CalcPEC_Start=NULL;
+	delete m_CalcPEC_Stop;m_CalcPEC_Stop=NULL;
 }
 
 int Operator_Multithread::CalcECOperator()
@@ -76,6 +85,9 @@ int Operator_Multithread::CalcECOperator()
 	delete m_CalcEC_Start;m_CalcEC_Start = new boost::barrier(m_numThreads+1); // numThread workers + 1 controller
 	delete m_CalcEC_Stop;m_CalcEC_Stop = new boost::barrier(m_numThreads+1); // numThread workers + 1 controller
 
+	delete m_CalcPEC_Start;m_CalcPEC_Start = new boost::barrier(m_numThreads+1); // numThread workers + 1 controller
+	delete m_CalcPEC_Stop;m_CalcPEC_Stop = new boost::barrier(m_numThreads+1); // numThread workers + 1 controller
+
 	unsigned int linesPerThread = round((float)numLines[0] / (float)m_numThreads);
 	for (unsigned int n=0; n<m_numThreads; n++)
 	{
@@ -104,6 +116,28 @@ bool Operator_Multithread::Calc_EC()
 	return true;
 }
 
+bool Operator_Multithread::CalcPEC()
+{
+	m_Nr_PEC[0]=0;	m_Nr_PEC[1]=0;	m_Nr_PEC[2]=0;
+
+	m_Nr_PEC_thread = new unsigned int[m_numThreads][3];
+
+	m_CalcPEC_Start->wait();
+
+	m_CalcPEC_Stop->wait();
+
+	for (unsigned int t=0;t<m_numThreads;++t)
+		for (int n=0;n<3;++n)
+			m_Nr_PEC[n]+=m_Nr_PEC_thread[t][n];
+
+	CalcPEC_Curves();
+
+	delete[] m_Nr_PEC_thread;
+
+	return true;
+}
+
+
 Operator_Thread::Operator_Thread( Operator_Multithread* ptr, unsigned int start, unsigned int stop, unsigned int threadID )
 {
 	m_start=start;
@@ -138,5 +172,13 @@ void Operator_Thread::operator()()
 		}
 	}
 	m_OpPtr->m_CalcEC_Stop->wait();
+
+	//************** calculate EC (Calc_EC) ***********************//
+	m_OpPtr->m_CalcPEC_Start->wait();
+	for (int n=0;n<3;++n)
+		m_OpPtr->m_Nr_PEC_thread[m_threadID][n] = 0;
+
+	m_OpPtr->CalcPEC_Range(m_start,m_stop,m_OpPtr->m_Nr_PEC_thread[m_threadID]);
+	m_OpPtr->m_CalcPEC_Stop->wait();
 }
 
diff --git a/FDTD/operator_multithread.h b/FDTD/operator_multithread.h
index 896753c..ddc17af 100644
--- a/FDTD/operator_multithread.h
+++ b/FDTD/operator_multithread.h
@@ -43,8 +43,16 @@ protected:
 
 	virtual bool Calc_EC(); //this method is using multi-threading
 
+	unsigned int (*m_Nr_PEC_thread)[3]; //count PEC edges per thread
+	virtual bool CalcPEC(); //this method is using multi-threading
+
+	//Calc_EC barrier
 	boost::barrier* m_CalcEC_Start;
 	boost::barrier* m_CalcEC_Stop;
+	//CalcPEC barrier
+	boost::barrier* m_CalcPEC_Start;
+	boost::barrier* m_CalcPEC_Stop;
+
 	boost::thread_group m_thread_group;
 	unsigned int m_numThreads; // number of worker threads
 };