Index: firmware/App/Monitors/Conductivity.h
===================================================================
diff -u -r337136fc77fe5628fa727aac6252a06238561a10 -r44dbba513dffd7b1a997f873426407dbfc4163d1
--- firmware/App/Monitors/Conductivity.h	(.../Conductivity.h)	(revision 337136fc77fe5628fa727aac6252a06238561a10)
+++ firmware/App/Monitors/Conductivity.h	(.../Conductivity.h)	(revision 44dbba513dffd7b1a997f873426407dbfc4163d1)
@@ -1,14 +1,14 @@
 /**************************************************************************
 *
-* Copyright (c) 2024-2024 Diality Inc. - All Rights Reserved.
+* Copyright (c) 2024-2025 Diality Inc. - All Rights Reserved.
 *
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
 * @file    Conductivity.h
 *
-* @author  (last)      Sean Nash
-* @date    (last)      09-Nov-2024
+* @author  (last)      Michael Garthwaite
+* @date    (last)      25-Jul-2025
 *
 * @author  (original)  Sean Nash
 * @date    (original)  09-Nov-2024
@@ -31,21 +31,39 @@
 
 // ********** public definitions **********
 
+#define RO_REJECTION_RATIO_OUT_OF_RANGE_VALUE    100.0F   ///< Out of range value for RO rejection ratio when CPi conductivity is zero.
+
 /// Conductivity data struct.
 typedef struct
 {
     F32 p9Conductivity;                                   ///< (P9) conductivity sensor value
     F32 p18Conductivity;                                  ///< (P18) conductivity sensor value
 } CONDUCTIVITY_DATA_T;
 
+/// RO rejection ratio data struct.
+typedef struct
+{
+    F32 rawRORejectionRatio;                                 ///< RO rejection ratio during tank full and fill state
+    F32 rawRORejectionRatioTankFill;                         ///< RO rejection ratio during tank fill state
+    F32 avgRORejectionRatio;                                 ///< RO rejection ratio average during tank full and fill state
+    F32 avgRORejectionRatioTankFill;                         ///< RO rejection ratio average during tank fill state
+    U32 genPermeateState;                                    ///< Permeate tank state
+} RO_REJECTION_RATIO_DATA_T;
+
 // ********** public function prototypes **********
 
 void initConductivity( void );
 void execConductivity( void );
 F32 getFilteredConductivity( CONDUCTIVITY_SENSORS_T sensor );
 F32 getFilteredConductivitySensorTemperature( CONDUCTIVITY_SENSORS_T sensor );
+F32 getRORejectonRatio( void );
+F32 getTankFillRORejectionRatio( void );
+F32 getRORRAverage( void );
+F32 getTankFillRORRAverage( void );
 
 BOOL testConductivitySensorDataPublishIntervalOverride( MESSAGE_T *message );
+BOOL testRORejectionRatioDataPublishIntervalOverride( MESSAGE_T *message );
+BOOL testRORejectionRatioFilteredOverride( MESSAGE_T *message );
 
 /**@}*/