Index: firmware/App/Controllers/PresOccl.c
===================================================================
diff -u -rced4d5be0d18c9b1001143206d10e09fd15f8efb -rab9ef60d5005db2a8e32353ee6c9bc7d743808aa
--- firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision ced4d5be0d18c9b1001143206d10e09fd15f8efb)
+++ firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision ab9ef60d5005db2a8e32353ee6c9bc7d743808aa)
@@ -99,6 +99,8 @@
 #define MIN_OCCLUSION_COUNTS                2000                                            ///< Minimum occlusion sensor reading for range check.
 #define OCCLUSION_CARTRIDGE_LOADED_PRESSURE_READING_MAX         24500                       ///< Occlusion sensors maximum pressure reading limit when cartridge is considered loaded.
 
+#define MAX_ART_VEN_OFFSET_MMHG             15.0F                                           ///< Maximum arterial/venous offset allowed.
+
 #define EMPTY_SALINE_BAG_THRESHOLD_MMHG     -300.0F                                         ///< Threshold below which the saline bag is considered empty (in mmHg).
 static const U32 EMPTY_SALINE_BAG_PERSISTENCE = ( 250 / TASK_GENERAL_INTERVAL );            ///< Time that saline bag looks empty before saying it is empty.
 
@@ -282,6 +284,10 @@
 {
     arterialPressureOffset = getMeasuredArterialPressure();
     venousPressureOffset   = getMeasuredVenousPressure();
+    if ( ( fabs( arterialPressureOffset ) > MAX_ART_VEN_OFFSET_MMHG ) || ( fabs( venousPressureOffset ) > MAX_ART_VEN_OFFSET_MMHG ) )
+    {
+        SET_ALARM_WITH_2_F32_DATA( ALARM_ID_HD_PRE_TREATMENT_DRY_PRESSURE_TEST_FAILURE, arterialPressureOffset, venousPressureOffset );
+    }
 }
 
 /*********************************************************************//**
@@ -680,7 +686,8 @@
         F32 venPresPSI;
 
         // Convert venous pressure to PSI and then mmHg
-        venPresPSI          = ( (F32)( venPres - VENOUS_PRESSURE_OFFSET ) * ( VENOUS_PRESSURE_MAX_PSI - VENOUS_PRESSURE_MIN_PSI ) / (F32)VENOUS_PRESSURE_SCALE ) + VENOUS_PRESSURE_MIN_PSI;
+        venPresPSI          = ( (F32)( venPres - VENOUS_PRESSURE_OFFSET ) *
+                                ( VENOUS_PRESSURE_MAX_PSI - VENOUS_PRESSURE_MIN_PSI ) / (F32)VENOUS_PRESSURE_SCALE ) + VENOUS_PRESSURE_MIN_PSI;
         venPresPSI          = venPresPSI * PSI_TO_MMHG;
         venousPressure.data = venPresPSI - venousPressureOffset;
     }