Index: firmware/App/Controllers/ConductivitySensors.h
===================================================================
diff -u -r6499ea25921fcf67826fa0c35bb03caf411ba542 -r5c430c3ac17fc8ad836fd70b8a3b8a12af44319e
--- firmware/App/Controllers/ConductivitySensors.h	(.../ConductivitySensors.h)	(revision 6499ea25921fcf67826fa0c35bb03caf411ba542)
+++ firmware/App/Controllers/ConductivitySensors.h	(.../ConductivitySensors.h)	(revision 5c430c3ac17fc8ad836fd70b8a3b8a12af44319e)
@@ -46,14 +46,16 @@
 
 // ********** public definitions **********
 
+#define RO_REJECTION_RATIO_OUT_OF_RANGE_VALUE    1.0F     ///< Out of range value for RO rejection ratio when CPi conductivity is zero.
+
 /// Enumeration of conductivity sensors.
 typedef enum ConductivitySensors
 {
-    CONDUCTIVITYSENSORS_CPI_SENSOR = 0,  ///< Inlet water conductivity sensor
-    CONDUCTIVITYSENSORS_CPO_SENSOR,      ///< Outlet water conductivity sensor
-    CONDUCTIVITYSENSORS_CD1_SENSOR,      ///< Post-acid concentrate conductivity sensor
-    CONDUCTIVITYSENSORS_CD2_SENSOR,      ///< Post-bicarbonate concentrate conductivity sensor
-    NUM_OF_CONDUCTIVITY_SENSORS          ///< Number of conductivity sensors
+    CONDUCTIVITYSENSORS_CPI_SENSOR = 0,     ///< Inlet water conductivity sensor
+    CONDUCTIVITYSENSORS_CPO_SENSOR,         ///< Outlet water conductivity sensor
+    CONDUCTIVITYSENSORS_CD1_SENSOR,         ///< Post-acid concentrate conductivity sensor
+    CONDUCTIVITYSENSORS_CD2_SENSOR,         ///< Post-bicarbonate concentrate conductivity sensor
+    NUM_OF_CONDUCTIVITY_SENSORS             ///< Number of conductivity sensors
 } CONDUCTIVITY_SENSORS_T;
 
 /// Conductivity data struct.
@@ -82,7 +84,6 @@
 SELF_TEST_STATUS_T execConductivitySensorsSelfTest( void );
 
 void checkInletWaterConductivity( void );
-void checkRORejectionRatio( void );
 
 F32 getConductivityValue( U32 sensorId );