diff --git a/src/main/java/Scienta.java b/src/main/java/Scienta.java
index 087e62d..904e00c 100644
--- a/src/main/java/Scienta.java
+++ b/src/main/java/Scienta.java
@@ -474,9 +474,12 @@ public class Scienta extends AreaDetector {
         ArrayList<Double> ret = new ArrayList<>();
         
         double[] spectrumZ = getSpectrumX();
-        if (spectrumZ.length>0){
+        if ((spectrumZ!=null) && (spectrumZ.length>0)){
             ret.add(spectrumZ[0]);
             ret.add(spectrumZ[spectrumZ.length-1]);
+        } else {
+            ret.add(0.0);
+            ret.add(0.0);            
         }
         /*
         //ret.add(getChannelBegin().getValue());