Index: firmware/App/Controllers/AirPump.c
===================================================================
diff -u -rf4816e953486acd06fe9c1592fc54731bdc840ce -r0299bdb0514a35999be37487ff332ecb3de163bd
--- firmware/App/Controllers/AirPump.c	(.../AirPump.c)	(revision f4816e953486acd06fe9c1592fc54731bdc840ce)
+++ firmware/App/Controllers/AirPump.c	(.../AirPump.c)	(revision 0299bdb0514a35999be37487ff332ecb3de163bd)
@@ -47,7 +47,7 @@
 
 static AIR_PUMP_STATE_T currentAirPumpState;                                                    ///< Current air pump control state.
 static U16 currentAirPumpRPM;                                                                   ///< Current air pump RPM.
-static F32 currentAirPumpPowerLevel;                                                            ///< Current air pump power level setting.
+static F32 currentAirPumpPowerLevel;                                                            ///< Current air pump power level setting in % duty cycle (0..100%).
 static U32 airPumpDataPublicationTimerCounter;                                                  ///< Air pump data broadcast timer counter.
 static OVERRIDE_U32_T airPumpDataPublishInterval;                                               ///< Air pump data broadcast interval (in ms).
 
Index: firmware/App/Drivers/GLXferPump.c
===================================================================
diff -u -rf267032333f872d729d33614f48373eeb6c422d2 -r0299bdb0514a35999be37487ff332ecb3de163bd
--- firmware/App/Drivers/GLXferPump.c	(.../GLXferPump.c)	(revision f267032333f872d729d33614f48373eeb6c422d2)
+++ firmware/App/Drivers/GLXferPump.c	(.../GLXferPump.c)	(revision 0299bdb0514a35999be37487ff332ecb3de163bd)
@@ -29,16 +29,17 @@
 // ********** private definitions **********
 
 #define AIR_PUMP_PWM_TIME           20                ///< Time (in 10ns increments) per PWM register count for the air pump = 20 kHz.
-#define AIR_PUMP_MAX_PWM            255.0f            ///< Air pump maximum PWM.
-#define AIR_PUMP_PWM_PCT            100.0f            ///< Air pump pwm percentage
+#define AIR_PUMP_MAX_PWM            255               ///< Air pump maximum PWM.
+#define AIR_PUMP_DUTY_CYCLE_MIN     0.0F              ///< Air pump minimum duty cycle in percentage
+#define AIR_PUMP_DUTY_CYCLE_MAX     100.0F            ///< Air pump maximum duty cycle in percentage
 
 // ********** private data **********
 
 static F32 currentAirPumpMotorPowerLevel;             ///< Current air pump motor state: 0=off, 1..255=power level.
 
 // ********** private function prototypes **********
 
-static U08 PercentageToScalar(F32 percentage);
+static U08 convertPercentageToScalar( F32 percentage );
 
 /*********************************************************************//**
  * @brief
@@ -48,7 +49,7 @@
  * @details \b Outputs: currentAirPumpMotorPowerLevel
  * @return none
  *************************************************************************/
-void initGasLiqXferPumpDriver(void)
+void initGasLiqXferPumpDriver( void )
 {
     currentAirPumpMotorPowerLevel = AIR_PUMP_MOTOR_OFF;
     setH12AirPumpMotorPowerLevel( currentAirPumpMotorPowerLevel );
@@ -58,7 +59,7 @@
 /*********************************************************************//**
  * @brief
  * The setAirPumpMotorPower function sets the air pump motor to the given
- * power level.
+ * power level in duty cycle percentage (0..100%).
  * @details \b Message \b Sent: MSG_ID_TD_EVENT if changing air pump power level.
  * @details \b Inputs: none
  * @details \b Outputs: currentAirPumpMotorPowerLevel
@@ -67,11 +68,12 @@
  *************************************************************************/
 void setAirPumpMotorPower( F32 power )
 {
+    U08 scalarPower = convertPercentageToScalar( power );
     // if state is changing, set the air pump to the given on/off state and send event
     if ( power != currentAirPumpMotorPowerLevel )
     {
-        SEND_EVENT_WITH_2_F32_DATA(TD_EVENT_AIR_PUMP_ON_OFF, currentAirPumpMotorPowerLevel, power );
-        setH12AirPumpMotorPowerLevel( PercentageToScalar( power ) );
+        SEND_EVENT_WITH_2_F32_DATA( TD_EVENT_AIR_PUMP_ON_OFF, currentAirPumpMotorPowerLevel, power );
+        setH12AirPumpMotorPowerLevel( scalarPower );
         currentAirPumpMotorPowerLevel = power;
     }
 }
@@ -110,19 +112,14 @@
  * @param percentage Power level for air pump (0...2=off, 3-100.0 for ON).
  * @return U08 8-bit PWM value (0-255)
  *************************************************************************/
-static U08 PercentageToScalar(F32 percentage) {
+static U08 convertPercentageToScalar( F32 percentage )
+{
+    F32 power;
     // Clamp input to 0-100%
-    if ( percentage < 0.0f )
-    {
-        percentage = 0.0f;
-    }
-    if ( percentage > AIR_PUMP_PWM_PCT )
-    {
-        percentage = AIR_PUMP_PWM_PCT;
-    }
+    power = RANGE( percentage, AIR_PUMP_DUTY_CYCLE_MIN, AIR_PUMP_DUTY_CYCLE_MAX );
 
-    // Calculate 0-255 value (255 * percent / 100)
-    return (U08)( ( ( percentage * AIR_PUMP_MAX_PWM ) / AIR_PUMP_PWM_PCT ) );
+    // Calculate 0-255 value (255 * power / 100)
+    return (U08)( ( ( power * AIR_PUMP_MAX_PWM ) / FRACTION_TO_PERCENT_FACTOR ) );
 }