diff --git a/src/main/java/neqsim/standards/gasquality/Standard_ISO6976.java b/src/main/java/neqsim/standards/gasquality/Standard_ISO6976.java
index 1df4d2deba..8b2bb40461 100644
--- a/src/main/java/neqsim/standards/gasquality/Standard_ISO6976.java
+++ b/src/main/java/neqsim/standards/gasquality/Standard_ISO6976.java
@@ -245,7 +245,6 @@ public void calculate() {
     Zmix20 -= Math.pow(Zmixtemp20, 2.0);
     molRefm3 =
         volRefP * 1.0e5 * 1.0 / (R * (getVolRefT() + 273.15) * getValue("CompressionFactor"));
-    // System.out.println("molRefm3 " + molRefm3);
   }
 
   /** {@inheritDoc} */
diff --git a/src/test/java/neqsim/standards/gasquality/Standard_ISO6976Test.java b/src/test/java/neqsim/standards/gasquality/Standard_ISO6976Test.java
index 1812a018ed..8ffd5708f2 100644
--- a/src/test/java/neqsim/standards/gasquality/Standard_ISO6976Test.java
+++ b/src/test/java/neqsim/standards/gasquality/Standard_ISO6976Test.java
@@ -5,6 +5,7 @@
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
+import neqsim.process.equipment.stream.Stream;
 import neqsim.thermo.system.SystemInterface;
 import neqsim.thermo.system.SystemSrkEos;
 import neqsim.thermodynamicoperations.ThermodynamicOperations;
@@ -164,6 +165,44 @@ void testCalculate2() {
      */
   }
 
+
+  @Test
+  void testCalculate3() {
+    SystemInterface testSystem = new SystemSrkEos(273.15, 1.0);
+    testSystem.addComponent("methane", 0.92470);
+    testSystem.addComponent("ethane", 0.035);
+    testSystem.addComponent("propane", 0.0098);
+    testSystem.addComponent("n-butane", 0.00220);
+    testSystem.addComponent("i-butane", 0.0034);
+    testSystem.addComponent("n-pentane", 0.0006);
+    testSystem.addComponent("nitrogen", 0.0175);
+    testSystem.addComponent("CO2", 0.0068);
+    testSystem.createDatabase(true);
+    testSystem.setMixingRule(2);
+
+    testSystem.init(0);
+    Standard_ISO6976 standard = new Standard_ISO6976(testSystem, 15, 15, "volume");
+    standard.setReferenceState("real");
+    standard.setReferenceType("volume");
+    standard.calculate();
+    Assertions.assertEquals(0.99764929782, standard.getValue("CompressionFactor"), 1e-3);
+    Assertions.assertEquals(35144.8789915, standard.getValue("InferiorCalorificValue"), 5);
+    Assertions.assertEquals(38959.473378295, standard.getValue("GCV"), 1e-5);
+
+    Assertions.assertEquals(50107.49824498, standard.getValue("SuperiorWobbeIndex"), 1e-5);
+    Assertions.assertEquals(45201.380041, standard.getValue("InferiorWobbeIndex"), 1e-5);
+
+    Assertions.assertEquals(0.60453397833045, standard.getValue("RelativeDensity"), 1e-5);
+    Assertions.assertEquals(0.99770997554, standard.getValue("CompressionFactor"), 1e-5);
+    Assertions.assertEquals(17.477845, standard.getValue("MolarMass"), 1e-5);
+
+    Stream testStream = new Stream("testStream", testSystem);
+    testStream.run();
+    Assertions.assertEquals(50107.49824498, testStream.getWI("volume", 15, 15) / 1e3, 1e-5);
+    Assertions.assertEquals(38959.473378, testStream.getGCV("volume", 15, 15) / 1e3, 1e-5);
+
+  }
+
   @Test
   @Disabled
   void testDisplay() {
diff --git a/src/test/java/neqsim/standards/gasquality/Standard_ISO6976_2016_Test.java b/src/test/java/neqsim/standards/gasquality/Standard_ISO6976_2016_Test.java
index 06f7ba3383..66b7272980 100644
--- a/src/test/java/neqsim/standards/gasquality/Standard_ISO6976_2016_Test.java
+++ b/src/test/java/neqsim/standards/gasquality/Standard_ISO6976_2016_Test.java
@@ -132,6 +132,37 @@ void testCalculate2() {
      */
   }
 
+  @Test
+  void testCalculate3() {
+    SystemInterface testSystem = new SystemSrkEos(273.15, 1.0);
+    testSystem.addComponent("methane", 0.92470);
+    testSystem.addComponent("ethane", 0.035);
+    testSystem.addComponent("propane", 0.0098);
+    testSystem.addComponent("n-butane", 0.00220);
+    testSystem.addComponent("i-butane", 0.0034);
+    testSystem.addComponent("n-pentane", 0.0006);
+    testSystem.addComponent("nitrogen", 0.0175);
+    testSystem.addComponent("CO2", 0.0068);
+    testSystem.createDatabase(true);
+    testSystem.setMixingRule(2);
+
+    testSystem.init(0);
+    Standard_ISO6976_2016 standard = new Standard_ISO6976_2016(testSystem, 15, 15, "volume");
+    standard.setReferenceState("real");
+    standard.setReferenceType("volume");
+    standard.calculate();
+    Assertions.assertEquals(0.99764929782, standard.getValue("CompressionFactor"), 1e-3);
+    Assertions.assertEquals(35144.8789915, standard.getValue("InferiorCalorificValue"), 5);
+    Assertions.assertEquals(38956.94693, standard.getValue("GCV"), 1e-5);
+
+    Assertions.assertEquals(50105.17975854, standard.getValue("SuperiorWobbeIndex"), 1e-5);
+    Assertions.assertEquals(45201.5624460, standard.getValue("InferiorWobbeIndex"), 1e-5);
+
+    Assertions.assertEquals(0.6045115156, standard.getValue("RelativeDensity"), 1e-5);
+    Assertions.assertEquals(0.99773023373, standard.getValue("CompressionFactor"), 1e-5);
+    Assertions.assertEquals(17.477288925, standard.getValue("MolarMass"), 1e-5);
+  }
+
   @Test
   @Disabled
   void testDisplay() {