diff --git a/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.C b/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.C
index 38efa9e858..43b876fbd6 100644
--- a/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.C
+++ b/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.C
@@ -64,7 +64,19 @@ Foam::basicChemistryModel::basicChemistryModel(const fvMesh& mesh)
     mesh_(mesh),
     chemistry_(lookup("chemistry")),
     deltaTChemIni_(readScalar(lookup("initialChemicalTimeStep"))),
-    deltaTChem_(mesh.nCells(), deltaTChemIni_)
+    deltaTChem_
+    (
+        IOobject
+        (
+            "deltaTChem",
+            mesh.time().constant(),
+            mesh,
+            IOobject::NO_READ,
+            IOobject::NO_WRITE
+        ),
+        mesh,
+        dimensionedScalar("deltaTChem0", dimTime, deltaTChemIni_)
+    )
 {}
 
 
diff --git a/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.H b/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.H
index 2f27d59f70..da54d4c916 100644
--- a/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.H
+++ b/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModel.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2012 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -40,6 +40,8 @@ SourceFiles
 #include "Switch.H"
 #include "scalarField.H"
 #include "volFieldsFwd.H"
+#include "volMesh.H"
+#include "DimensionedField.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -80,14 +82,14 @@ protected:
         const scalar deltaTChemIni_;
 
         //- Latest estimation of integration step
-        scalarField deltaTChem_;
+        DimensionedField<scalar, volMesh> deltaTChem_;
 
 
     // Protected Member Functions
 
         //- Return non-const access to the latest estimation of integration
         //  step, e.g. for multi-chemistry model
-        scalarField& deltaTChem();
+        inline DimensionedField<scalar, volMesh>& deltaTChem();
 
         //- Correct function - updates due to mesh changes
         void correct();
@@ -118,7 +120,7 @@ public:
         inline Switch chemistry() const;
 
         //- Return the latest estimation of integration step
-        inline const scalarField& deltaTChem() const;
+        inline const DimensionedField<scalar, volMesh>& deltaTChem() const;
 
 
         // Functions to be derived in derived classes
@@ -126,7 +128,10 @@ public:
             // Fields
 
                 //- Return const access to chemical source terms [kg/m3/s]
-                virtual tmp<volScalarField> RR(const label i) const = 0;
+                virtual const DimensionedField<scalar, volMesh>& RR
+                (
+                    const label i
+                ) const = 0;
 
 
             // Chemistry solution
diff --git a/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModelI.H b/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModelI.H
index eeec0af749..6455309e15 100644
--- a/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModelI.H
+++ b/src/thermophysicalModels/chemistryModel/chemistryModel/basicChemistryModel/basicChemistryModelI.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2012 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -37,13 +37,15 @@ inline Foam::Switch Foam::basicChemistryModel::chemistry() const
 }
 
 
-inline const Foam::scalarField& Foam::basicChemistryModel::deltaTChem() const
+inline const Foam::DimensionedField<Foam::scalar, Foam::volMesh>&
+Foam::basicChemistryModel::deltaTChem() const
 {
     return deltaTChem_;
 }
 
 
-inline Foam::scalarField& Foam::basicChemistryModel::deltaTChem()
+inline Foam::DimensionedField<Foam::scalar, Foam::volMesh>&
+Foam::basicChemistryModel::deltaTChem()
 {
     return deltaTChem_;
 }