diff --git a/src/Vts.Test/Unit/Modeling/ForwardSolvers/DiffusionParametersTests.cs b/src/Vts.Test/Unit/Modeling/ForwardSolvers/DiffusionParametersTests.cs
new file mode 100644
index 000000000..a4bdd15e3
--- /dev/null
+++ b/src/Vts.Test/Unit/Modeling/ForwardSolvers/DiffusionParametersTests.cs
@@ -0,0 +1,85 @@
+using System;
+using System.IO;
+using NUnit.Framework;
+using Vts.Modeling.ForwardSolvers;
+
+namespace Vts.Test.Unit.Modeling.ForwardSolvers
+{
+    [TestFixture]
+    public class DiffusionParametersTests
+    {
+        /// <summary>
+        /// Test to verify results of Create Method
+        /// </summary>
+        [Test]
+        public void Validate_Create_method_results()
+        {
+            // test SDA
+            var ops = new OpticalProperties(0.01, 1.0, 0.8, 1.4);
+            var diffusionParameters = DiffusionParameters.Create(
+                ops,
+                ForwardModel.SDA);
+            Assert.IsTrue(Math.Abs(2.950078 - diffusionParameters.A) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.330033 - diffusionParameters.D) < 1e-6);
+            Assert.IsTrue(Math.Abs(214.13747 - diffusionParameters.cn) < 1e-4);
+            Assert.IsTrue(Math.Abs(0.8 - diffusionParameters.gTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.01 - diffusionParameters.mua) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.174068 - diffusionParameters.mueff) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.0 - diffusionParameters.musTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.01 - diffusionParameters.mutTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.01 - diffusionParameters.mutr) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.947246 - diffusionParameters.zb) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.990099 - diffusionParameters.zp) < 1e-6);
+            // test deltaP1=
+            diffusionParameters = DiffusionParameters.Create(
+                ops,
+                ForwardModel.DeltaPOne);
+            Assert.IsTrue(Math.Abs(2.950078 - diffusionParameters.A) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.330033 - diffusionParameters.D) < 1e-6);
+            Assert.IsTrue(Math.Abs(214.13747 - diffusionParameters.cn) < 1e-4);
+            Assert.IsTrue(Math.Abs(0.444444 - diffusionParameters.gTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.01 - diffusionParameters.mua) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.174068 - diffusionParameters.mueff) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.799999 - diffusionParameters.musTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.809999 - diffusionParameters.mutTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.01 - diffusionParameters.mutr) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.947246 - diffusionParameters.zb) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.552486 - diffusionParameters.zp) < 1e-6);
+            // add test to test warning if Mua >= Musp
+            ops = new OpticalProperties(1.0, 1.0, 0.8, 1.4);
+            var output = new StringWriter();
+            Console.SetOut(output);
+            diffusionParameters = DiffusionParameters.Create(
+                ops,
+                ForwardModel.SDA);
+            Assert.IsTrue(diffusionParameters != null);
+            Assert.That(output.ToString(), Is.EqualTo("Warning: Mua >= Musp\r\n"));
+        }
+
+        /// <summary>
+        /// Test to verify results of Copy Method
+        /// </summary>
+        [Test]
+        public void Validate_Copy_method_results()
+        {
+            // set diffusion parameters
+            var ops = new OpticalProperties(0.01, 1.0, 0.8, 1.4);
+            var originalDiffusionParameters = DiffusionParameters.Create(
+                ops,
+                ForwardModel.SDA);
+            // copy the parameters
+            var diffusionParameters = DiffusionParameters.Copy(originalDiffusionParameters);
+            Assert.IsTrue(Math.Abs(2.950078 - diffusionParameters.A) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.330033 - diffusionParameters.D) < 1e-6);
+            Assert.IsTrue(Math.Abs(214.13747 - diffusionParameters.cn) < 1e-4);
+            Assert.IsTrue(Math.Abs(0.8 - diffusionParameters.gTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.01 - diffusionParameters.mua) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.174068 - diffusionParameters.mueff) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.0 - diffusionParameters.musTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.01 - diffusionParameters.mutTilde) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.01 - diffusionParameters.mutr) < 1e-6);
+            Assert.IsTrue(Math.Abs(1.947246 - diffusionParameters.zb) < 1e-6);
+            Assert.IsTrue(Math.Abs(0.990099 - diffusionParameters.zp) < 1e-6);
+        }
+    }
+}
diff --git a/src/Vts/Modeling/ForwardSolvers/DiffusionParameters.cs b/src/Vts/Modeling/ForwardSolvers/DiffusionParameters.cs
index 03f02b26a..c299825e3 100644
--- a/src/Vts/Modeling/ForwardSolvers/DiffusionParameters.cs
+++ b/src/Vts/Modeling/ForwardSolvers/DiffusionParameters.cs
@@ -58,6 +58,9 @@ public static DiffusionParameters Create(OpticalProperties op, ForwardModel fm)
             var tempMutTilde = op.Mua + tempMusTilde;
             var tempZp = 1 / tempMutTilde;
 
+            // put out warning if mus' on order of mua
+            if (op.Mua >= op.Musp) Console.WriteLine("Warning: Mua >= Musp");
+
             return new DiffusionParameters(tempA, tempMueff, tempZb, tempZp, tempMutTilde, tempMusTilde, tempMutr, tempGTilde, tempD, tempCn, tempMua);
         }