public static CalibrateWindow OpenCalibrateWindow(MainWindow mainWindow)
 {
     if (_instance == null)
     {
         _instance = new CalibrateWindow(mainWindow);
     }
     return(_instance);
 }
 /// <summary>
 /// Called when the Close button in the top right is pressed
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 public void WindowClosing(object sender, CancelEventArgs e)
 {
     _instance = null;
 }