Index: firmware/App/Modes/Prime.c
===================================================================
diff -u -r2d354e7ca9b55c5bb4fe679c8dd43fcbafd53d42 -r24237b8f12f5bb4c9cfa8c51b3b1a92d2d692631
--- firmware/App/Modes/Prime.c	(.../Prime.c)	(revision 2d354e7ca9b55c5bb4fe679c8dd43fcbafd53d42)
+++ firmware/App/Modes/Prime.c	(.../Prime.c)	(revision 24237b8f12f5bb4c9cfa8c51b3b1a92d2d692631)
@@ -55,6 +55,9 @@
 #define PRIME_SALINE_DIALYZER_TIME_LIMIT                    ( 300 * MS_PER_SECOND )                     ///< Five minutes time limit for priming saline dialyzer path.
 #define CIRC_BUF_SIZE                                       10                                          ///< Size of the circular buffer.  Note: the size is not 2^N where N = 1, 2 , 3, 4, 5 ...
 #define MAX_BUF_INDEX                                       ( CIRC_BUF_SIZE - 1 )                       ///< Use to calculate write index of the circular buffer.
+#define PRIME_DIALYZER_BYPASS_EXPECTED_VOLUME               1000.0                                      ///< Prime dialysate dialyzer bypass state expected steady state volume in mL.
+#define PRIME_DIALYZER_EXPECTED_VOLUME                      1200.0                                      ///< Prime dialysate dialyzer state expected steady state volume in mL.
+#define PRIME_EXPECTED_VOLUME_TOLERANCE                     50.0                                        ///< Prime expected steady state volume tolerance in mL.
 
 /// States of the treatment reservoir management state machine.
 typedef enum PrimeReservoirMgmt_States
@@ -651,10 +654,12 @@
         F32 const currentLoadCellValue = getLoadCellWeight( LOAD_CELL_RESERVOIR_1_PRIMARY );
         F32 const previousLoadCellValue = loadcellReadings[ iteration % CIRC_BUF_SIZE ];
         F32 const loadcellDelta = fabs( currentLoadCellValue - previousLoadCellValue );  // delta of the current (now) and the previous (10 seconds ago)
-        loadcellReadings[ ( iteration + MAX_BUF_INDEX ) % CIRC_BUF_SIZE ] = currentLoadCellValue;  // see Circular Buffer.xlsx in X:\Engineering\Denali\06- Software Design\Story\HD\HD Pre-Treatment Prime Update
-        iteration++;  // iteration will not roll over in 136 years at one second increment
+        loadcellReadings[ ( iteration + MAX_BUF_INDEX ) % CIRC_BUF_SIZE ] = currentLoadCellValue;
+        iteration++;
 
-        if ( loadcellDelta < LOAD_CELL_VOLUME_NOISE_TOLERANCE )  // TODO: also check for the expected reservoir volume here
+        if ( ( loadcellDelta < LOAD_CELL_VOLUME_NOISE_TOLERANCE  ) &&
+             ( currentLoadCellValue < ( PRIME_DIALYZER_BYPASS_EXPECTED_VOLUME + PRIME_EXPECTED_VOLUME_TOLERANCE ) ) &&  // check the steady state volume of R1
+             ( currentLoadCellValue > ( PRIME_DIALYZER_BYPASS_EXPECTED_VOLUME - PRIME_EXPECTED_VOLUME_TOLERANCE ) ) )
         {
 #ifdef RUN_BLOOD_CIRCUIT_PRIME_AGAIN
             if ( TRUE == runBloodCircuitPrimeAgain )
@@ -757,7 +762,9 @@
         loadcellReadings[ ( iteration + MAX_BUF_INDEX ) % CIRC_BUF_SIZE ] = currentLoadCellValue;
         iteration++;
 
-        if ( loadcellDelta < LOAD_CELL_VOLUME_NOISE_TOLERANCE )  // TODO: also check for the expected reservoir volume here
+        if ( ( loadcellDelta < LOAD_CELL_VOLUME_NOISE_TOLERANCE  ) &&
+             ( currentLoadCellValue < ( PRIME_DIALYZER_EXPECTED_VOLUME + PRIME_EXPECTED_VOLUME_TOLERANCE ) ) &&  // check the steady state volume of R2
+             ( currentLoadCellValue > ( PRIME_DIALYZER_EXPECTED_VOLUME - PRIME_EXPECTED_VOLUME_TOLERANCE ) ) )
         {
             signalDialOutPumpHardStop();
             transitionToWetSelfTests();