Index: dialin/hd/air_bubbles.py
===================================================================
diff -u -rab9f086590a97f92856343bba1263dafa39a566f -r801527f052cc3ca768d768401164c0072892442d
--- dialin/hd/air_bubbles.py	(.../air_bubbles.py)	(revision ab9f086590a97f92856343bba1263dafa39a566f)
+++ dialin/hd/air_bubbles.py	(.../air_bubbles.py)	(revision 801527f052cc3ca768d768401164c0072892442d)
@@ -31,6 +31,10 @@
     ADV: Air bubble Detector Venous
     """
 
+    # Air bubble detectors
+    ADA = 0  # Air bubble Detector Arterial
+    ADV = 1  # Air bubble Detector Venous
+
     # Air bubble detectors status
     BUBBLE_DETECTED_STATUS = 0   # Air bubble detected
     FLUID_DETECTED_STATUS = 1    # Fluid (no air bubble) detected
@@ -100,7 +104,7 @@
             Must be logged into HD.
             Given detector must be one of the detectors listed below.
 
-        @param detected:  unsigned int - detected (0=air bubble, 1=fluid) to override detector with
+        @param status:  unsigned int - status (0=air bubble, 1=fluid) to override detector with
         @param index: integer - 0 for ADA status override, 1 for ADV status override
         @param reset:  integer - 1 to reset a previous override, 0 to override
         @return: 1 if successful, zero otherwise
@@ -115,9 +119,9 @@
                                               message_id=MsgIds.MSG_ID_HD_BUBBLE_STATUS_OVERRIDE.value,
                                               payload=payload)
 
-        if index == 0:
+        if index == self.ADA:
             self.logger.debug("Override air bubble detector ADA status value")
-        elif index == 1:
+        elif index == self.ADV:
             self.logger.debug("Override air bubble detector ADV status value")
 
         # Send message
@@ -147,9 +151,9 @@
                                               message_id=MsgIds.MSG_ID_HD_BUBBLES_SELF_TEST_REQUEST.value,
                                               payload=payload)
 
-        if index == 0:
+        if index == self.ADA:
             self.logger.debug("Request air bubble self-test for detector ADA")
-        elif index == 1:
+        elif index == self.ADV:
             self.logger.debug("Request air bubble self-test for detector ADV")
 
         # Send message
Index: tests/hd_air_bubbles_data.py
===================================================================
diff -u -ra09fdc812d51f12d6e9a3639c3f8bcb29536b853 -r801527f052cc3ca768d768401164c0072892442d
--- tests/hd_air_bubbles_data.py	(.../hd_air_bubbles_data.py)	(revision a09fdc812d51f12d6e9a3639c3f8bcb29536b853)
+++ tests/hd_air_bubbles_data.py	(.../hd_air_bubbles_data.py)	(revision 801527f052cc3ca768d768401164c0072892442d)
@@ -20,6 +20,10 @@
 from time import sleep
 
 if __name__ == "__main__":
+    # Air bubble detectors
+    ADA = 0  # Air bubble Detector Arterial
+    ADV = 1  # Air bubble Detector Venous
+
     # Create an HD object called hd
     hd = HD()
     sleep(2)
@@ -29,9 +33,9 @@
     #hd.air_bubbles.cmd_air_bubbles_data_broadcast_interval_override(100)
 
     # Self-test state
-    #hd.air_bubbles.cmd_air_bubble_self_test_request(0)
+    #hd.air_bubbles.cmd_air_bubble_self_test_request(ADA)
     #sleep(0.1)
-    #hd.air_bubbles.cmd_air_bubble_self_test_request(1)
+    #hd.air_bubbles.cmd_air_bubble_self_test_request(ADV)
     #sleep(0.1)
 
     while True: