diff --git a/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy b/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy
index 0a22fff4..60578c96 100644
--- a/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy
+++ b/numass-main/src/main/groovy/inr/numass/scripts/Underflow.groovy
@@ -10,6 +10,8 @@ import hep.dataforge.io.ColumnedDataWriter
 import hep.dataforge.storage.commons.StorageUtils
 import hep.dataforge.tables.Table
 import inr.numass.data.NumassDataUtils
+import inr.numass.data.api.NumassPoint
+import inr.numass.data.api.NumassSet
 import inr.numass.data.storage.NumassStorage
 import inr.numass.data.storage.NumassStorageFactory
 import inr.numass.utils.UnderflowCorrection
@@ -21,13 +23,14 @@ File rootDir = new File("D:\\Work\\Numass\\data\\2017_05\\Fill_1")
 
 NumassStorage storage = NumassStorageFactory.buildLocal(rootDir);
 
-Collection<NumassPointImpl> data = NumassDataUtils.joinSpectra(
+NumassSet data = NumassDataUtils.join(
+        "data",
         StorageUtils.loaderStream(storage)
                 .filter { it.key.matches("set_.{1,3}") }
                 .map {
-            println "loading ${it.key}"
-            it.value
-        }.map { (NumassData) it }
+                    println "loading ${it.key}"
+                    it.value
+                }.collect { (NumassSet) it }
 )
 
 data = NumassDataUtils.substractReferencePoint(data, 18600d);
@@ -53,8 +56,8 @@ data = NumassDataUtils.substractReferencePoint(data, 18600d);
 //    }
 //}
 
-def printPoint(Iterable<NumassPointImpl> data, List<Double> us, int binning = 20, normalize = true) {
-    List<NumassPointImpl> points = data.findAll { it.voltage in us }.sort { it.voltage }
+def printPoint(Iterable<NumassPoint> data, List<Double> us, int binning = 20, normalize = true) {
+    List<NumassPoint> points = data.findAll { it.voltage in us }.sort { it.voltage }
 
     Map spectra = points.first().getMap(binning, normalize).collectEntries { key, value ->
         [key, [value]]
diff --git a/numass-main/src/main/groovy/inr/numass/scripts/times/MultiPointHistogram.groovy b/numass-main/src/main/groovy/inr/numass/scripts/times/MultiPointHistogram.groovy
index 1f8b34a6..dae24e69 100644
--- a/numass-main/src/main/groovy/inr/numass/scripts/times/MultiPointHistogram.groovy
+++ b/numass-main/src/main/groovy/inr/numass/scripts/times/MultiPointHistogram.groovy
@@ -2,12 +2,14 @@ package inr.numass.scripts.times
 
 import hep.dataforge.context.Context
 import hep.dataforge.context.Global
+import hep.dataforge.grind.Grind
 import hep.dataforge.grind.GrindShell
 import hep.dataforge.grind.helpers.PlotHelper
 import hep.dataforge.plots.fx.FXPlotManager
 import inr.numass.NumassPlugin
 import inr.numass.data.PointAnalyzer
 import inr.numass.data.analyzers.TimeAnalyzer
+import inr.numass.data.api.MetaBlock
 import inr.numass.data.api.NumassPoint
 import inr.numass.data.storage.NumassDataLoader
 import inr.numass.data.storage.NumassStorage
@@ -30,19 +32,21 @@ new GrindShell(ctx).eval {
 
     def pattern = "set_.{1,2}"
 
-    List<NumassDataLoader> loaders = storage.loaders().findAll{it.name.matches(pattern)}.collect{it as NumassDataLoader}
+    List<NumassDataLoader> loaders = storage.loaders().findAll { it.name.matches(pattern) }.collect {
+        it as NumassDataLoader
+    }
 
     println "Found ${loaders.size()} loaders matching pattern"
 
     def hv = 16000.toString();
-    List<NumassPoint> points = loaders.collect { loader -> loader.optPoint(hv).get()}
+    List<NumassPoint> points = loaders.collect { loader -> loader.optPoint(hv).get() }
 
     def loChannel = 400;
     def upChannel = 800;
 
-    def chain = new TimeAnalyzer().timeChain(loChannel,upChannel, points as NumassPoint[])
+    def chain = new TimeAnalyzer().timeChain(new MetaBlock(points), Grind.buildMeta("window.lo": loChannel, "window.up": upChannel))
 
-    def histogram = PointAnalyzer.histogram(chain, 5e-6,500).asTable();
+    def histogram = PointAnalyzer.histogram(chain, 5e-6, 500).asTable();
 
     println "finished histogram calculation..."
 
diff --git a/numass-server/src/main/java/inr/numass/server/NumassStorageHandler.java b/numass-server/src/main/java/inr/numass/server/NumassStorageHandler.java
index 73649b82..a0da00c9 100644
--- a/numass-server/src/main/java/inr/numass/server/NumassStorageHandler.java
+++ b/numass-server/src/main/java/inr/numass/server/NumassStorageHandler.java
@@ -13,6 +13,7 @@ import hep.dataforge.server.storage.StorageRatpackHandler;
 import hep.dataforge.storage.api.ObjectLoader;
 import hep.dataforge.storage.api.PointLoader;
 import hep.dataforge.storage.api.Storage;
+import inr.numass.data.api.NumassSet;
 import org.slf4j.LoggerFactory;
 import ratpack.handling.Context;
 
@@ -45,7 +46,7 @@ public class NumassStorageHandler extends StorageRatpackHandler {
     @Override
     @SuppressWarnings("unchecked")
     protected void renderObjects(Context ctx, ObjectLoader<?> loader) {
-        if (loader instanceof NumassData) {
+        if (loader instanceof NumassSet) {
 
         } else if (NumassRun.RUN_NOTES.equals(loader.getName())) {
             try {