diff --git a/numass-main/src/main/java/inr/numass/actions/MonitorCorrectAction.java b/numass-main/src/main/java/inr/numass/actions/MonitorCorrectAction.java
index 56b462e7..68f6ed12 100644
--- a/numass-main/src/main/java/inr/numass/actions/MonitorCorrectAction.java
+++ b/numass-main/src/main/java/inr/numass/actions/MonitorCorrectAction.java
@@ -30,8 +30,7 @@ import hep.dataforge.tables.MapPoint;
 import hep.dataforge.tables.Table;
 import hep.dataforge.values.Value;
 import java.io.OutputStream;
-import java.time.LocalDateTime;
-import java.time.ZoneId;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map.Entry;
@@ -58,7 +57,7 @@ public class MonitorCorrectAction extends OneToOneAction<Table, Table> {
 
         double monitor = meta.getDouble("monitorPoint", Double.NaN);
 
-        TreeMap<LocalDateTime, DataPoint> index = getMonitorIndex(monitor, sourceData);
+        TreeMap<Instant, DataPoint> index = getMonitorIndex(monitor, sourceData);
         if (index.isEmpty()) {
             log.reportError("No monitor points found");
             return sourceData;
@@ -82,9 +81,9 @@ public class MonitorCorrectAction extends OneToOneAction<Table, Table> {
             MapPoint.Builder pb = new MapPoint.Builder(dp);
             pb.putValue("Monitor", 1.0);
             if (!isMonitorPoint(monitor, dp) || index.isEmpty()) {
-                LocalDateTime time = getTime(dp);
-                Entry<LocalDateTime, DataPoint> previousMonitor = index.floorEntry(time);
-                Entry<LocalDateTime, DataPoint> nextMonitor = index.ceilingEntry(time);
+                Instant time = getTime(dp);
+                Entry<Instant, DataPoint> previousMonitor = index.floorEntry(time);
+                Entry<Instant, DataPoint> nextMonitor = index.ceilingEntry(time);
 
                 if (previousMonitor == null) {
                     previousMonitor = nextMonitor;
@@ -95,10 +94,14 @@ public class MonitorCorrectAction extends OneToOneAction<Table, Table> {
                 }
 
                 double p;
-//                p = (getTime(dp).toEpochMilli() - previousMonitor.getKey().toEpochMilli())/
-                p = 0.5;
+                if (nextMonitor.getKey().isAfter(time) && time.isAfter(previousMonitor.getKey())) {
+                    p = 1.0 * (time.toEpochMilli() - previousMonitor.getKey().toEpochMilli())
+                            / (nextMonitor.getKey().toEpochMilli() - previousMonitor.getKey().toEpochMilli());
+                } else {
+                    p = 0.5;
+                }
 
-                double corrFactor = (getCR(previousMonitor.getValue()) * p + getCR(nextMonitor.getValue()) * (1 - p)) / norm;
+                double corrFactor = (getCR(previousMonitor.getValue()) * (1 - p) + getCR(nextMonitor.getValue()) * p) / norm;
                 double corrErr = previousMonitor.getValue().getValue("CRerr").doubleValue() / getCR(previousMonitor.getValue());
                 double pointErr = dp.getValue("CRerr").doubleValue() / getCR(dp);
                 double err = Math.sqrt(corrErr * corrErr + pointErr * pointErr) * getCR(dp);
@@ -156,8 +159,8 @@ public class MonitorCorrectAction extends OneToOneAction<Table, Table> {
         return point.getValue("Uset").doubleValue() == monitor;
     }
 
-    private LocalDateTime getTime(DataPoint point) {
-        return LocalDateTime.ofInstant(point.getValue("Timestamp").timeValue(), ZoneId.systemDefault());
+    private Instant getTime(DataPoint point) {
+        return point.getValue("Timestamp").timeValue();
     }
 
     private int getTotal(DataPoint point) {
@@ -168,8 +171,8 @@ public class MonitorCorrectAction extends OneToOneAction<Table, Table> {
         return point.getValue("CR").doubleValue();
     }
 
-    private TreeMap<LocalDateTime, DataPoint> getMonitorIndex(double monitor, Iterable<DataPoint> data) {
-        TreeMap<LocalDateTime, DataPoint> res = new TreeMap<>();
+    private TreeMap<Instant, DataPoint> getMonitorIndex(double monitor, Iterable<DataPoint> data) {
+        TreeMap<Instant, DataPoint> res = new TreeMap<>();
         for (DataPoint dp : data) {
             if (isMonitorPoint(monitor, dp)) {
                 res.put(getTime(dp), dp);
diff --git a/numass-main/src/main/java/inr/numass/workbench/StagePane.java b/numass-main/src/main/java/inr/numass/workbench/StagePane.java
index 5908ba57..cc121c8c 100644
--- a/numass-main/src/main/java/inr/numass/workbench/StagePane.java
+++ b/numass-main/src/main/java/inr/numass/workbench/StagePane.java
@@ -39,6 +39,7 @@ public class StagePane extends TabPane implements Named {
     public synchronized void closeTab(String name) {
         tabs.get(name).close();
         Platform.runLater(() -> getTabs().remove(tabs.get(name)));
+        tabs.remove(name);
     }
 
     public synchronized TextOutputTab buildTextOutput(String name) {
diff --git a/numass-storage/src/main/java/inr/numass/storage/NumassDataLoader.java b/numass-storage/src/main/java/inr/numass/storage/NumassDataLoader.java
index f7c794a8..81498925 100644
--- a/numass-storage/src/main/java/inr/numass/storage/NumassDataLoader.java
+++ b/numass-storage/src/main/java/inr/numass/storage/NumassDataLoader.java
@@ -26,10 +26,9 @@ import hep.dataforge.meta.MetaBuilder;
 import hep.dataforge.storage.api.ObjectLoader;
 import hep.dataforge.storage.api.Storage;
 import hep.dataforge.storage.loaders.AbstractLoader;
-import hep.dataforge.tables.ListTable;
 import hep.dataforge.tables.Table;
+import hep.dataforge.values.Value;
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
@@ -42,10 +41,9 @@ import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Scanner;
 import java.util.function.Function;
 import java.util.function.Supplier;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import org.apache.commons.vfs2.FileObject;
 import org.apache.commons.vfs2.FileSystemException;
@@ -177,9 +175,9 @@ public class NumassDataLoader extends AbstractLoader implements ObjectLoader<Env
         while (buffer.hasRemaining()) {
             try {
                 short channel = (short) Short.toUnsignedInt(buffer.getShort());
-                long time = Integer.toUnsignedLong(buffer.getInt());
+                long length = Integer.toUnsignedLong(buffer.getInt());
                 byte status = buffer.get();
-                NMEvent event = new NMEvent(channel, (double) time * timeCoef * 1e-9);
+                NMEvent event = new NMEvent(channel, (double) length * timeCoef * 1e-9);
                 events.add(event);
             } catch (Exception ex) {
                 //LoggerFactory.getLogger(MainDataReader.class).error("Error in data format", ex);
@@ -333,12 +331,17 @@ public class NumassDataLoader extends AbstractLoader implements ObjectLoader<Env
 
     @Override
     public Instant startTime() {
-        if (meta().hasValue("file.timeCreated")) {
-            return meta().getValue("file.timeCreated").timeValue();
+        //Temporary substitution for meta tag
+        Envelope hvEnvelope = getHVEnvelope();
+        if (hvEnvelope != null) {
+            try {
+                return Value.of(new Scanner(hvEnvelope.getData().getStream()).next()).timeValue();
+            } catch (IOException ex) {
+                return null;
+            }
         } else {
             return null;
         }
-
     }
 
     @Override
diff --git a/numass-viewer/src/main/java/inr/numass/viewer/MainViewerController.java b/numass-viewer/src/main/java/inr/numass/viewer/MainViewerController.java
index a2e33b2f..1eefb069 100644
--- a/numass-viewer/src/main/java/inr/numass/viewer/MainViewerController.java
+++ b/numass-viewer/src/main/java/inr/numass/viewer/MainViewerController.java
@@ -21,7 +21,6 @@ import hep.dataforge.context.ProcessManager;
 import hep.dataforge.exceptions.StorageException;
 import hep.dataforge.fx.ConsoleFragment;
 import hep.dataforge.fx.ProcessManagerFragment;
-import inr.numass.NumassContext;
 import inr.numass.NumassProperties;
 import inr.numass.storage.NumassData;
 import inr.numass.storage.NumassStorage;
diff --git a/numass-viewer/src/main/java/inr/numass/viewer/NumassLoaderTreeBuilder.java b/numass-viewer/src/main/java/inr/numass/viewer/NumassLoaderTreeBuilder.java
index b5265a15..9c4856d1 100644
--- a/numass-viewer/src/main/java/inr/numass/viewer/NumassLoaderTreeBuilder.java
+++ b/numass-viewer/src/main/java/inr/numass/viewer/NumassLoaderTreeBuilder.java
@@ -38,26 +38,14 @@ import org.slf4j.LoggerFactory;
  */
 public class NumassLoaderTreeBuilder {
 
-//    private final TreeTableView<TreeItemValue> numassLoaderDataTree;
-//    private final NumassStorage rootStorage;
-//    private final Consumer<NumassData> numassViewBuilder;
-//
-//    public NumassLoaderTreeBuilder(TreeTableView<TreeItemValue> numassLoaderDataTree, NumassStorage rootStorage, Consumer<NumassData> numassViewBuilder) {
-//        this.numassLoaderDataTree = numassLoaderDataTree;
-//        this.rootStorage = rootStorage;
-//        this.numassViewBuilder = numassViewBuilder;
-//    }
     public void build(ProcessManager.Callback callback,
             TreeTableView<TreeItemValue> numassLoaderDataTree,
             NumassStorage rootStorage,
             Consumer<NumassData> numassViewBuilder) throws StorageException {
 
-//                callback.updateTitle("Load numass data (" + rootStorage.getName() + ")");
         TreeItem<TreeItemValue> root = buildNode(rootStorage, numassViewBuilder, callback);
-//        callback.updateMessage("finished loading numass tree");
         root.setExpanded(true);
 
-//        numassLoaderDataTree.setShowRoot(true);
         Platform.runLater(() -> {
             numassLoaderDataTree.setRoot(root);
 
@@ -76,6 +64,8 @@ public class NumassLoaderTreeBuilder {
 
             numassLoaderDataTree.getColumns().setAll(numassLoaderNameColumn, numassLoaderTimeColumn, nummassLoaderDescriptionColumn);
 
+            numassLoaderNameColumn.setSortType(TreeTableColumn.SortType.ASCENDING);
+            numassLoaderDataTree.getSortOrder().addAll(numassLoaderTimeColumn, numassLoaderNameColumn);
             numassLoaderDataTree.addEventHandler(MouseEvent.MOUSE_CLICKED, (MouseEvent e) -> {
                 if (e.getClickCount() == 2) {
                     TreeItemValue value = numassLoaderDataTree.getFocusModel().getFocusedCell().getTreeItem().getValue();
@@ -92,17 +82,6 @@ public class NumassLoaderTreeBuilder {
 
     private TreeItem<TreeItemValue> buildNode(NumassStorage storage,
             Consumer<NumassData> numassViewBuilder, ProcessManager.Callback callback) throws StorageException {
-//        CompletableFuture<TreeItem<TreeItemValue>> future = CompletableFuture.supplyAsync(() -> {
-//            try {
-//                TreeItem<TreeItemValue> node = new TreeItem<>(buildValue(storage));
-//                node.getChildren().setAll(buildChildren(storage, numassViewBuilder, callback));
-//                return node;
-//            } catch (StorageException ex) {
-//                throw new RuntimeException(ex);
-//            }
-//        });
-//        callback.getProcess().addChild(storage.getName(), future);
-//        return future.join();
         TreeItem<TreeItemValue> node = new TreeItem<>(buildValue(storage));
         node.getChildren().setAll(buildChildren(storage, numassViewBuilder, callback));
         return node;
diff --git a/numass-viewer/src/main/resources/fxml/MainView.fxml b/numass-viewer/src/main/resources/fxml/MainView.fxml
index 3ed5e6c7..bcf314de 100644
--- a/numass-viewer/src/main/resources/fxml/MainView.fxml
+++ b/numass-viewer/src/main/resources/fxml/MainView.fxml
@@ -16,6 +16,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 -->
 
+<?import java.lang.*?>
+<?import javafx.geometry.*?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+<?import javafx.scene.text.*?>
+<?import org.controlsfx.control.*?>
 <?import javafx.geometry.Insets?>
 <?import javafx.scene.control.Button?>
 <?import javafx.scene.control.Label?>
@@ -32,7 +38,7 @@ limitations under the License.
 <?import javafx.scene.text.Font?>
 <?import org.controlsfx.control.StatusBar?>
 
-<AnchorPane id="AnchorPane" prefHeight="768.0" prefWidth="1024.0" xmlns="http://javafx.com/javafx/8.0.65" xmlns:fx="http://javafx.com/fxml/1" fx:controller="inr.numass.viewer.MainViewerController">
+<AnchorPane id="AnchorPane" prefHeight="768.0" prefWidth="1024.0" xmlns="http://javafx.com/javafx/8.0.40" xmlns:fx="http://javafx.com/fxml/1" fx:controller="inr.numass.viewer.MainViewerController">
     <children>
         <BorderPane prefHeight="200.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
          <top>