diff --git a/Software/PC_Application/Application.pro b/Software/PC_Application/Application.pro
index c1a8681..28a273d 100644
--- a/Software/PC_Application/Application.pro
+++ b/Software/PC_Application/Application.pro
@@ -33,6 +33,7 @@ HEADERS += \
     Traces/tracewidget.h \
     Traces/tracexyplot.h \
     Traces/xyplotaxisdialog.h \
+    VNA/portextension.h \
     VNA/vna.h \
     appwindow.h \
     averaging.h \
@@ -78,6 +79,7 @@ SOURCES += \
     Traces/tracewidget.cpp \
     Traces/tracexyplot.cpp \
     Traces/xyplotaxisdialog.cpp \
+    VNA/portextension.cpp \
     VNA/vna.cpp \
     appwindow.cpp \
     averaging.cpp \
@@ -111,6 +113,7 @@ FORMS += \
     Traces/traceimportdialog.ui \
     Traces/tracewidget.ui \
     Traces/xyplotaxisdialog.ui \
+    VNA/portextensioneditdialog.ui \
     main.ui \
     preferencesdialog.ui
 
diff --git a/Software/PC_Application/Calibration/calibration.cpp b/Software/PC_Application/Calibration/calibration.cpp
index 77c5a2d..dc62c9f 100644
--- a/Software/PC_Application/Calibration/calibration.cpp
+++ b/Software/PC_Application/Calibration/calibration.cpp
@@ -44,7 +44,7 @@ bool Calibration::calculationPossible(Calibration::Type type)
 {
     return SanityCheckSamples(Measurements(type, false));
 }
-
+#include <QDebug>
 bool Calibration::constructErrorTerms(Calibration::Type type)
 {
     if(!calculationPossible(type)) {
@@ -700,7 +700,7 @@ istream& operator >>(istream &in, Calibration &c)
         }
         for(auto t : Calibration::Types()) {
             if(Calibration::TypeToString(t) == QString::fromStdString(line)) {
-                // try to apply this calibration type
+                // try to P2 this calibration type
                 if(c.calculationPossible(t)) {
                     c.constructErrorTerms(t);
                 } else {
diff --git a/Software/PC_Application/Calibration/calkit.cpp b/Software/PC_Application/Calibration/calkit.cpp
index 6f06f01..970267b 100644
--- a/Software/PC_Application/Calibration/calkit.cpp
+++ b/Software/PC_Application/Calibration/calkit.cpp
@@ -239,7 +239,7 @@ double Calkit::minFreq(bool TRL)
         return TRL_line_minfreq;
     } else {
         fillTouchstoneCache();
-        double min = std::numeric_limits<double>::min();
+        double min = 0;
         array<Touchstone*, 4> ts_list = {ts_open, ts_short, ts_load, ts_through};
         // find the highest minimum frequency in all measurement files
         for(auto ts : ts_list) {
diff --git a/Software/PC_Application/VNA/portextension.cpp b/Software/PC_Application/VNA/portextension.cpp
new file mode 100644
index 0000000..6558261
--- /dev/null
+++ b/Software/PC_Application/VNA/portextension.cpp
@@ -0,0 +1,233 @@
+#include "portextension.h"
+#include "ui_portextensioneditdialog.h"
+#include <QCheckBox>
+#include <cmath>
+
+using namespace std;
+
+PortExtension::PortExtension()
+    : QObject()
+{
+    port1.enabled = false;
+    port1.frequency = 0;
+    port1.loss = 0;
+    port1.DCloss = 0;
+    port1.delay = 0;
+    port1.velocityFactor = 0.66;
+    port2.enabled = false;
+    port2.frequency = 0;
+    port2.loss = 0;
+    port2.DCloss = 0;
+    port2.delay = 0;
+    port2.velocityFactor = 0.66;
+
+    measuring = false;
+    kit = nullptr;
+}
+
+void PortExtension::applyToMeasurement(Protocol::Datapoint &d)
+{
+    if(measuring) {
+        if(measurements.size() > 0) {
+            if(d.pointNum == 0) {
+                // sweep complete, evaluate measurement
+                // TODO
+                if(msgBox) {
+                    msgBox->close();
+                    msgBox = nullptr;
+                }
+            } else {
+                measurements.push_back(d);
+            }
+        } else if(d.pointNum == 0) {
+            // first point of sweep, start measurement
+            measurements.push_back(d);
+        }
+    }
+
+    if(port1.enabled || port2.enabled) {
+        // Convert measurements to complex variables
+        auto S11 = complex<double>(d.real_S11, d.imag_S11);
+        auto S21 = complex<double>(d.real_S21, d.imag_S21);
+        auto S22 = complex<double>(d.real_S22, d.imag_S22);
+        auto S12 = complex<double>(d.real_S12, d.imag_S12);
+
+        if(port1.enabled) {
+            auto phase = -2 * M_PI * port1.delay * d.frequency;
+            auto db_attennuation = port1.DCloss;
+            if(port1.frequency != 0) {
+                db_attennuation += port1.loss * sqrt(d.frequency / port1.frequency);
+            }
+            // convert from db to factor
+            auto att = pow(10.0, -db_attennuation / 20.0);
+            auto correction = polar<double>(att, phase);
+            S11 /= correction * correction;
+            S21 /= correction;
+            S12 /= correction;
+        }
+        if(port2.enabled) {
+            auto phase = -2 * M_PI * port2.delay * d.frequency;
+            auto db_attennuation = port2.DCloss;
+            if(port2.frequency != 0) {
+                db_attennuation += port2.loss * sqrt(d.frequency / port2.frequency);
+            }
+            // convert from db to factor
+            auto att = pow(10.0, -db_attennuation / 20.0);
+            auto correction = polar<double>(att, phase);
+            S22 /= correction * correction;
+            S21 /= correction;
+            S12 /= correction;
+        }
+        d.real_S11 = S11.real();
+        d.imag_S11 = S11.imag();
+        d.real_S12 = S12.real();
+        d.imag_S12 = S12.imag();
+        d.real_S21 = S21.real();
+        d.imag_S21 = S21.imag();
+        d.real_S22 = S22.real();
+        d.imag_S22 = S22.imag();
+    }
+}
+
+void PortExtension::edit()
+{
+    constexpr double c = 299792458;
+
+    auto dialog = new QDialog();
+    auto ui = new Ui::PortExtensionEditDialog();
+    ui->setupUi(dialog);
+
+    // set initial values
+    ui->P1Time->setUnit("s");
+    ui->P1Time->setPrefixes("pnum ");
+    ui->P1Distance->setUnit("m");
+    ui->P1Distance->setPrefixes("m ");
+    ui->P1DCloss->setUnit("db");
+    ui->P1Loss->setUnit("db");
+    ui->P1Frequency->setUnit("Hz");
+    ui->P1Frequency->setPrefixes(" kMG");
+    ui->P1Time->setValue(port1.delay);
+    ui->P1Velocity->setValue(port1.velocityFactor);
+    ui->P1Distance->setValue(port1.delay * port1.velocityFactor * c);
+    ui->P1DCloss->setValue(port1.DCloss);
+    ui->P1Loss->setValue(port1.loss);
+    ui->P1Frequency->setValue(port1.frequency);
+    if(!kit) {
+        ui->P1calkit->setEnabled(false);
+    }
+
+    ui->P2Time->setUnit("s");
+    ui->P2Time->setPrefixes("pnum ");
+    ui->P2Distance->setUnit("m");
+    ui->P2Distance->setPrefixes("m ");
+    ui->P2DCloss->setUnit("db");
+    ui->P2Loss->setUnit("db");
+    ui->P2Frequency->setUnit("Hz");
+    ui->P2Frequency->setPrefixes(" kMG");
+    ui->P2Time->setValue(port2.delay);
+    ui->P2Velocity->setValue(port2.velocityFactor);
+    ui->P2Distance->setValue(port2.delay * port2.velocityFactor * c);
+    ui->P2DCloss->setValue(port2.DCloss);
+    ui->P2Loss->setValue(port2.loss);
+    ui->P2Frequency->setValue(port2.frequency);
+    if(!kit) {
+        ui->P2calkit->setEnabled(false);
+    }
+
+    // connections to link delay and distance
+    connect(ui->P1Time, &SIUnitEdit::valueChanged, [=](double newval) {
+        ui->P1Distance->setValueQuiet(newval * ui->P1Velocity->value() * c);
+    });
+    connect(ui->P1Distance, &SIUnitEdit::valueChanged, [=](double newval) {
+        ui->P1Time->setValueQuiet(newval / (ui->P1Velocity->value() * c));
+    });
+    connect(ui->P1Velocity, &SIUnitEdit::valueChanged, [=](double newval) {
+        ui->P1Time->setValueQuiet(ui->P1Distance->value() / (newval * c));
+    });
+    connect(ui->P1short, &QPushButton::pressed, [=](){
+        isOpen = false;
+        isPort1 = true;
+        isIdeal = ui->P1ideal->isChecked();
+        startMeasurement();
+    });
+    connect(ui->P1open, &QPushButton::pressed, [=](){
+        isOpen = true;
+        isPort1 = true;
+        isIdeal = ui->P1ideal->isChecked();
+        startMeasurement();
+    });
+
+    connect(ui->P2Time, &SIUnitEdit::valueChanged, [=](double newval) {
+        ui->P2Distance->setValueQuiet(newval * ui->P2Velocity->value() * c);
+    });
+    connect(ui->P2Distance, &SIUnitEdit::valueChanged, [=](double newval) {
+        ui->P2Time->setValueQuiet(newval / (ui->P2Velocity->value() * c));
+    });
+    connect(ui->P2Velocity, &SIUnitEdit::valueChanged, [=](double newval) {
+        ui->P2Time->setValueQuiet(ui->P2Distance->value() / (newval * c));
+    });
+    connect(ui->P2short, &QPushButton::pressed, [=](){
+        isOpen = false;
+        isPort1 = false;
+        isIdeal = ui->P2ideal->isChecked();
+        startMeasurement();
+    });
+    connect(ui->P2open, &QPushButton::pressed, [=](){
+        isOpen = true;
+        isPort1 = false;
+        isIdeal = ui->P2ideal->isChecked();
+        startMeasurement();
+    });
+
+    connect(ui->buttonBox, &QDialogButtonBox::accepted, [=](){
+        port1.delay = ui->P1Time->value();
+        port1.velocityFactor = ui->P1Velocity->value();
+        port1.DCloss = ui->P1DCloss->value();
+        port1.loss = ui->P1Loss->value();
+        port1.frequency = ui->P1Frequency->value();
+        port2.delay = ui->P2Time->value();
+        port2.velocityFactor = ui->P2Velocity->value();
+        port2.DCloss = ui->P2DCloss->value();
+        port2.loss = ui->P2Loss->value();
+        port2.frequency = ui->P2Frequency->value();
+        dialog->accept();
+    });
+    connect(ui->buttonBox, &QDialogButtonBox::rejected, dialog, &QDialog::reject);
+    dialog->show();
+}
+
+void PortExtension::startMeasurement()
+{
+    measurements.clear();
+    msgBox = new QMessageBox(QMessageBox::Information, "Auto port extension", "Taking measurement...", QMessageBox::Cancel);
+    connect(msgBox, &QMessageBox::rejected, [=]() {
+        measuring = false;
+        measurements.clear();
+    });
+    msgBox->show();
+    measuring = true;
+}
+
+QToolBar *PortExtension::createToolbar()
+{
+    auto tb = new QToolBar("Port Extension");
+    auto editButton = new QPushButton("Port Extension");
+    auto p1enable = new QCheckBox("Port 1");
+    auto p2enable = new QCheckBox("Port 2");
+    connect(p1enable, &QCheckBox::clicked, [=]() {
+        port1.enabled = p1enable->isChecked();
+    });
+    connect(p2enable, &QCheckBox::clicked, [=]() {
+        port2.enabled = p2enable->isChecked();
+    });
+    connect(editButton, &QPushButton::pressed, this, &PortExtension::edit);
+    tb->addWidget(editButton);
+    tb->addWidget(p1enable);
+    tb->addWidget(p2enable);
+    return tb;
+}
+
+void PortExtension::setCalkit(Calkit *kit)
+{
+    this->kit = kit;
+}
diff --git a/Software/PC_Application/VNA/portextension.h b/Software/PC_Application/VNA/portextension.h
new file mode 100644
index 0000000..a7d145e
--- /dev/null
+++ b/Software/PC_Application/VNA/portextension.h
@@ -0,0 +1,44 @@
+#ifndef PORTEXTENSION_H
+#define PORTEXTENSION_H
+
+#include <QObject>
+#include "../VNA_embedded/Application/Communication/Protocol.hpp"
+#include <QToolBar>
+#include "Calibration/calkit.h"
+#include <QMessageBox>
+
+class PortExtension : public QObject
+{
+    Q_OBJECT
+public:
+    PortExtension();
+    void applyToMeasurement(Protocol::Datapoint& d);
+    QToolBar *createToolbar();
+    void setCalkit(Calkit *kit);
+public slots:
+    void edit();
+
+private:
+    void startMeasurement();
+    class Extension {
+    public:
+        bool enabled;
+        double delay;
+        double velocityFactor;
+        double DCloss;
+        double loss;
+        double frequency;
+    };
+    Extension port1, port2;
+
+    // status variables for automatic measurements
+    Calkit *kit;
+    bool measuring;
+    bool isPort1;
+    bool isOpen;
+    bool isIdeal;
+    std::vector<Protocol::Datapoint> measurements;
+    QMessageBox *msgBox;
+};
+
+#endif // PORTEXTENSION_H
diff --git a/Software/PC_Application/VNA/portextensiondialog.h b/Software/PC_Application/VNA/portextensiondialog.h
new file mode 100644
index 0000000..59fc420
--- /dev/null
+++ b/Software/PC_Application/VNA/portextensiondialog.h
@@ -0,0 +1,25 @@
+#ifndef PORTEXTENSIONDIALOG_H
+#define PORTEXTENSIONDIALOG_H
+
+#include <QDialog>
+
+namespace Ui {
+class PortExtensionDialog;
+}
+
+class PortExtensionDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit PortExtensionDialog(QWidget *parent = nullptr);
+    ~PortExtensionDialog();
+
+private slots:
+    void on_buttonBox_accepted();
+
+private:
+    Ui::PortExtensionDialog *ui;
+};
+
+#endif // PORTEXTENSIONDIALOG_H
diff --git a/Software/PC_Application/VNA/portextensioneditdialog.ui b/Software/PC_Application/VNA/portextensioneditdialog.ui
new file mode 100644
index 0000000..f63dba1
--- /dev/null
+++ b/Software/PC_Application/VNA/portextensioneditdialog.ui
@@ -0,0 +1,334 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>PortExtensionEditDialog</class>
+ <widget class="QDialog" name="PortExtensionEditDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>318</width>
+    <height>476</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Port Extension</string>
+  </property>
+  <property name="modal">
+   <bool>true</bool>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout_3">
+   <item>
+    <widget class="QTabWidget" name="tabWidget">
+     <property name="currentIndex">
+      <number>0</number>
+     </property>
+     <widget class="QWidget" name="tab">
+      <attribute name="title">
+       <string>Port 1</string>
+      </attribute>
+      <layout class="QVBoxLayout" name="verticalLayout_7">
+       <item>
+        <widget class="QGroupBox" name="groupBox">
+         <property name="title">
+          <string>Delay</string>
+         </property>
+         <layout class="QFormLayout" name="formLayout">
+          <item row="0" column="0">
+           <widget class="QLabel" name="label">
+            <property name="text">
+             <string>Distance:</string>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="1">
+           <widget class="SIUnitEdit" name="P1Distance"/>
+          </item>
+          <item row="1" column="0">
+           <widget class="QLabel" name="label_2">
+            <property name="text">
+             <string>Time:</string>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="1">
+           <widget class="SIUnitEdit" name="P1Time"/>
+          </item>
+          <item row="2" column="0">
+           <widget class="QLabel" name="label_3">
+            <property name="text">
+             <string>Velocity Factor:</string>
+            </property>
+           </widget>
+          </item>
+          <item row="2" column="1">
+           <widget class="SIUnitEdit" name="P1Velocity"/>
+          </item>
+         </layout>
+        </widget>
+       </item>
+       <item>
+        <widget class="QGroupBox" name="groupBox_2">
+         <property name="title">
+          <string>Loss</string>
+         </property>
+         <layout class="QVBoxLayout" name="verticalLayout">
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_2">
+            <item>
+             <widget class="QLabel" name="label_4">
+              <property name="text">
+               <string>At DC:</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="SIUnitEdit" name="P1DCloss"/>
+            </item>
+            <item>
+             <spacer name="horizontalSpacer">
+              <property name="orientation">
+               <enum>Qt::Horizontal</enum>
+              </property>
+              <property name="sizeHint" stdset="0">
+               <size>
+                <width>40</width>
+                <height>20</height>
+               </size>
+              </property>
+             </spacer>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout">
+            <item>
+             <widget class="SIUnitEdit" name="P1Loss"/>
+            </item>
+            <item>
+             <widget class="QLabel" name="label_5">
+              <property name="text">
+               <string>at</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="SIUnitEdit" name="P1Frequency"/>
+            </item>
+           </layout>
+          </item>
+         </layout>
+        </widget>
+       </item>
+       <item>
+        <widget class="QGroupBox" name="groupBox_3">
+         <property name="title">
+          <string>Determine automatically</string>
+         </property>
+         <layout class="QVBoxLayout" name="verticalLayout_2">
+          <item>
+           <widget class="QRadioButton" name="P1ideal">
+            <property name="text">
+             <string>Assume ideal open/short</string>
+            </property>
+            <property name="checked">
+             <bool>true</bool>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <widget class="QRadioButton" name="P1calkit">
+            <property name="text">
+             <string>Use definition from calibration kit</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_3">
+            <item>
+             <widget class="QPushButton" name="P1short">
+              <property name="text">
+               <string>Measure short</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QPushButton" name="P1open">
+              <property name="text">
+               <string>Measure open</string>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </item>
+         </layout>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+     <widget class="QWidget" name="tab_2">
+      <attribute name="title">
+       <string>Port 2</string>
+      </attribute>
+      <layout class="QVBoxLayout" name="verticalLayout_6">
+       <item>
+        <widget class="QGroupBox" name="groupBox_6">
+         <property name="title">
+          <string>Delay</string>
+         </property>
+         <layout class="QFormLayout" name="formLayout_2">
+          <item row="0" column="0">
+           <widget class="QLabel" name="label_8">
+            <property name="text">
+             <string>Distance:</string>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="1">
+           <widget class="SIUnitEdit" name="P2Distance"/>
+          </item>
+          <item row="1" column="0">
+           <widget class="QLabel" name="label_9">
+            <property name="text">
+             <string>Time:</string>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="1">
+           <widget class="SIUnitEdit" name="P2Time"/>
+          </item>
+          <item row="2" column="0">
+           <widget class="QLabel" name="label_10">
+            <property name="text">
+             <string>Velocity Factor:</string>
+            </property>
+           </widget>
+          </item>
+          <item row="2" column="1">
+           <widget class="SIUnitEdit" name="P2Velocity"/>
+          </item>
+         </layout>
+        </widget>
+       </item>
+       <item>
+        <widget class="QGroupBox" name="groupBox_5">
+         <property name="title">
+          <string>Loss</string>
+         </property>
+         <layout class="QVBoxLayout" name="verticalLayout_5">
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_5">
+            <item>
+             <widget class="QLabel" name="label_6">
+              <property name="text">
+               <string>At DC:</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="SIUnitEdit" name="P2DCloss"/>
+            </item>
+            <item>
+             <spacer name="horizontalSpacer_2">
+              <property name="orientation">
+               <enum>Qt::Horizontal</enum>
+              </property>
+              <property name="sizeHint" stdset="0">
+               <size>
+                <width>40</width>
+                <height>20</height>
+               </size>
+              </property>
+             </spacer>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_6">
+            <item>
+             <widget class="SIUnitEdit" name="P2Loss"/>
+            </item>
+            <item>
+             <widget class="QLabel" name="label_7">
+              <property name="text">
+               <string>at</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="SIUnitEdit" name="P2Frequency"/>
+            </item>
+           </layout>
+          </item>
+         </layout>
+        </widget>
+       </item>
+       <item>
+        <widget class="QGroupBox" name="groupBox_4">
+         <property name="title">
+          <string>Determine automatically</string>
+         </property>
+         <layout class="QVBoxLayout" name="verticalLayout_4">
+          <item>
+           <widget class="QRadioButton" name="P2ideal">
+            <property name="text">
+             <string>Assume ideal open/short</string>
+            </property>
+            <property name="checked">
+             <bool>true</bool>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <widget class="QRadioButton" name="P2calkit">
+            <property name="text">
+             <string>Use definition from calibration kit</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_4">
+            <item>
+             <widget class="QPushButton" name="P2short">
+              <property name="text">
+               <string>Measure short</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QPushButton" name="P2open">
+              <property name="text">
+               <string>Measure open</string>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </item>
+         </layout>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>SIUnitEdit</class>
+   <extends>QLineEdit</extends>
+   <header>CustomWidgets/siunitedit.h</header>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/Software/PC_Application/VNA/vna.cpp b/Software/PC_Application/VNA/vna.cpp
index 0f896aa..d85d416 100644
--- a/Software/PC_Application/VNA/vna.cpp
+++ b/Software/PC_Application/VNA/vna.cpp
@@ -109,6 +109,7 @@ VNA::VNA(AppWindow *window)
     connect(calEditKit, &QAction::triggered, [=](){
         cal.getCalibrationKit().edit();
     });
+    portExtension.setCalkit(&cal.getCalibrationKit());
 
     // Tools menu
     auto toolsMenu = new QMenu("Tools");
@@ -310,6 +311,10 @@ VNA::VNA(AppWindow *window)
     window->addToolBar(tb_cal);
     toolbars.insert(tb_cal);
 
+    auto tb_portExtension = portExtension.createToolbar();
+    window->addToolBar(tb_portExtension);
+    toolbars.insert(tb_portExtension);
+
 
     markerModel = new TraceMarkerModel(traceModel);
 
@@ -379,6 +384,7 @@ void VNA::initializeDevice()
         if(QFile::exists(filename)) {
             cal.openFromFile(filename);
             ApplyCalibration(cal.getType());
+            portExtension.setCalkit(&cal.getCalibrationKit());
         }
         removeDefaultCal->setEnabled(true);
     } else {
@@ -418,6 +424,8 @@ void VNA::NewDatapoint(Protocol::Datapoint d)
     if(calValid) {
         cal.correctMeasurement(d);
     }
+    portExtension.applyToMeasurement(d);
+
     traceModel.addVNAData(d);
     emit dataChanged();
     if(d.pointNum == settings.points - 1) {
diff --git a/Software/PC_Application/VNA/vna.h b/Software/PC_Application/VNA/vna.h
index 48f6917..e92e376 100644
--- a/Software/PC_Application/VNA/vna.h
+++ b/Software/PC_Application/VNA/vna.h
@@ -8,6 +8,7 @@
 #include "CustomWidgets/tilewidget.h"
 #include "Device/device.h"
 #include <functional>
+#include "portextension.h"
 
 class VNA : public Mode
 {
@@ -69,6 +70,8 @@ private:
     QMenu *defaultCalMenu;
     QAction *assignDefaultCal, *removeDefaultCal;
 
+    PortExtension portExtension;
+
     // Status Labels
     QLabel *lAverages;