diff --git a/src/Base/UnitsSchema.h b/src/Base/UnitsSchema.h
index 0e7d8842c9..c2c1f1b736 100644
--- a/src/Base/UnitsSchema.h
+++ b/src/Base/UnitsSchema.h
@@ -60,7 +60,7 @@ public:
     virtual void resetSchemaUnits(void){}
 
     /// This method translates the quantity in a string as the user may expect it.
-    virtual QString schemaTranslate(Base::Quantity quant,double &factor,QString &unitString)=0;
+    virtual QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString)=0;
 };
 
 
diff --git a/src/Base/UnitsSchemaCentimeters.cpp b/src/Base/UnitsSchemaCentimeters.cpp
index 2e4b34f5a8..501b6c3a1d 100644
--- a/src/Base/UnitsSchemaCentimeters.cpp
+++ b/src/Base/UnitsSchemaCentimeters.cpp
@@ -36,7 +36,7 @@
 using namespace Base;
 
 
-QString UnitsSchemaCentimeters::schemaTranslate(Base::Quantity quant,double &factor,QString &unitString)
+QString UnitsSchemaCentimeters::schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString)
 {
     Unit unit = quant.getUnit();
     if (unit == Unit::Length) {
diff --git a/src/Base/UnitsSchemaCentimeters.h b/src/Base/UnitsSchemaCentimeters.h
index e8366d267f..2ca513759a 100644
--- a/src/Base/UnitsSchemaCentimeters.h
+++ b/src/Base/UnitsSchemaCentimeters.h
@@ -37,8 +37,7 @@ namespace Base {
 class UnitsSchemaCentimeters: public UnitsSchema
 {
 public:
-    virtual QString schemaTranslate(Base::Quantity quant,double &factor,QString &unitString);
-
+    virtual QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString);
 };
 
 } // namespace Base
diff --git a/src/Base/UnitsSchemaImperial1.cpp b/src/Base/UnitsSchemaImperial1.cpp
index f4a476a409..d07ae65eb8 100644
--- a/src/Base/UnitsSchemaImperial1.cpp
+++ b/src/Base/UnitsSchemaImperial1.cpp
@@ -58,7 +58,7 @@ using namespace Base;
 //    Quantity::Mile =  Quantity (1609344.0     ,Unit(1));
 //}
 
-QString UnitsSchemaImperial1::schemaTranslate(Base::Quantity quant,double &factor,QString &unitString)
+QString UnitsSchemaImperial1::schemaTranslate(const Quantity &quant, double &factor, QString &unitString)
 {
     double UnitValue = std::abs(quant.getValue());
     Unit unit = quant.getUnit();
@@ -140,7 +140,7 @@ QString UnitsSchemaImperial1::schemaTranslate(Base::Quantity quant,double &facto
     return QString::fromUtf8("%1 %2").arg(Ln).arg(unitString);
 }
 
-QString UnitsSchemaImperialDecimal::schemaTranslate(Base::Quantity quant,double &factor,QString &unitString)
+QString UnitsSchemaImperialDecimal::schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString)
 {
     double UnitValue = std::abs(quant.getValue());
     Unit unit = quant.getUnit();
@@ -205,7 +205,7 @@ QString UnitsSchemaImperialDecimal::schemaTranslate(Base::Quantity quant,double
     return QString::fromUtf8("%1 %2").arg(Ln).arg(unitString);
 }
 
-QString UnitsSchemaImperialBuilding::schemaTranslate(Base::Quantity quant,double &factor,QString &unitString)
+QString UnitsSchemaImperialBuilding::schemaTranslate(const Quantity &quant, double &factor, QString &unitString)
 {
     // this schema expresses distances in feet + inches + fractions
     // ex: 3'- 4 1/4"
diff --git a/src/Base/UnitsSchemaImperial1.h b/src/Base/UnitsSchemaImperial1.h
index 214ec4a2a2..9ae4a66109 100644
--- a/src/Base/UnitsSchemaImperial1.h
+++ b/src/Base/UnitsSchemaImperial1.h
@@ -41,7 +41,7 @@ class UnitsSchemaImperial1: public UnitsSchema
 public:
     //virtual void setSchemaUnits(void);
     //virtual void resetSchemaUnits(void);
-    virtual QString schemaTranslate(Base::Quantity quant,double &factor,QString &unitString);
+    virtual QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString);
 };
 
 /** The schema class for the imperial unit system
@@ -53,7 +53,7 @@ class UnitsSchemaImperialDecimal: public UnitsSchema
 public:
     //virtual void setSchemaUnits(void);
     //virtual void resetSchemaUnits(void);
-    virtual QString schemaTranslate(Base::Quantity quant,double &factor,QString &unitString);
+    virtual QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString);
 };
 
 /** The schema class for the imperial unit system
@@ -65,7 +65,7 @@ class UnitsSchemaImperialBuilding: public UnitsSchema
 public:
     //virtual void setSchemaUnits(void);
     //virtual void resetSchemaUnits(void);
-    virtual QString schemaTranslate(Base::Quantity quant,double &factor,QString &unitString);
+    virtual QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString);
 };
 
 
diff --git a/src/Base/UnitsSchemaInternal.cpp b/src/Base/UnitsSchemaInternal.cpp
index f80d2fca0f..7d95535dce 100644
--- a/src/Base/UnitsSchemaInternal.cpp
+++ b/src/Base/UnitsSchemaInternal.cpp
@@ -37,7 +37,7 @@
 using namespace Base;
 
 
-QString UnitsSchemaInternal::schemaTranslate(Base::Quantity quant,double &factor,QString &unitString)
+QString UnitsSchemaInternal::schemaTranslate(const Quantity &quant, double &factor, QString &unitString)
 {
     double UnitValue = std::abs(quant.getValue());
     Unit unit = quant.getUnit();
diff --git a/src/Base/UnitsSchemaInternal.h b/src/Base/UnitsSchemaInternal.h
index c37449e61b..eabf74db62 100644
--- a/src/Base/UnitsSchemaInternal.h
+++ b/src/Base/UnitsSchemaInternal.h
@@ -40,7 +40,7 @@ namespace Base {
 class UnitsSchemaInternal: public UnitsSchema
 {
 public:
-    virtual QString schemaTranslate(Base::Quantity quant,double &factor,QString &unitString);
+    virtual QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString);
 };
 
 
diff --git a/src/Base/UnitsSchemaMKS.cpp b/src/Base/UnitsSchemaMKS.cpp
index 50b7990281..46f6176341 100644
--- a/src/Base/UnitsSchemaMKS.cpp
+++ b/src/Base/UnitsSchemaMKS.cpp
@@ -36,7 +36,7 @@
 using namespace Base;
 
 
-QString UnitsSchemaMKS::schemaTranslate(Base::Quantity quant,double &factor,QString &unitString)
+QString UnitsSchemaMKS::schemaTranslate(const Quantity &quant, double &factor, QString &unitString)
 {
     double UnitValue = std::abs(quant.getValue());
     Unit unit = quant.getUnit();
diff --git a/src/Base/UnitsSchemaMKS.h b/src/Base/UnitsSchemaMKS.h
index 19712eb2d2..9cd52228e5 100644
--- a/src/Base/UnitsSchemaMKS.h
+++ b/src/Base/UnitsSchemaMKS.h
@@ -38,7 +38,7 @@ namespace Base {
 class UnitsSchemaMKS: public UnitsSchema
 {
 public:
-    virtual QString schemaTranslate(Base::Quantity quant,double &factor,QString &unitString);
+    virtual QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString);
 };