Index: firmware/App/Controllers/PresOccl.c
===================================================================
diff -u -r9353792f6dbd624a1d55cf1e87fa848e8fbaea71 -rb91f035a7268b2aa22ad50cf1081aad4b2f5c5e9
--- firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision 9353792f6dbd624a1d55cf1e87fa848e8fbaea71)
+++ firmware/App/Controllers/PresOccl.c	(.../PresOccl.c)	(revision b91f035a7268b2aa22ad50cf1081aad4b2f5c5e9)
@@ -98,6 +98,8 @@
 #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.
 
@@ -281,6 +283,10 @@
 {
     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 );
+    }
 }
 
 /*********************************************************************//**
@@ -679,7 +685,8 @@
         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;
     }