Index: firmware/App/Controllers/DialOutFlow.c
===================================================================
diff -u -rd265eb0baf2ef0d293125dc48177ed3077d20ab8 -r90945afbe3866bf383c44c2a1f52438192c267c5
--- firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision d265eb0baf2ef0d293125dc48177ed3077d20ab8)
+++ firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision 90945afbe3866bf383c44c2a1f52438192c267c5)
@@ -102,13 +102,14 @@
 #define DOP_ML_PER_MIN_TO_PUMP_RPM_FACTOR       ( DOP_REV_PER_LITER / ML_PER_LITER )   ///< Conversion factor from mL/min to pump motor RPM.
 #define DOP_GEAR_RATIO                          32.0F           ///< Pump motor to pump gear ratio.
 #define DOP_PWM_ZERO_OFFSET                     0.1F            ///< 10% PWM duty cycle = zero speed.
+#define DOP_100_PCT_PWM_RPM_RANGE               4000.0F         ///< 10-90% PWM range yields 0-3,200 RPM range.  Full 100% PWM range would yield 4,000 RPM range.
 
 /// Macro converts a flow rate to an estimated PWM duty cycle %.
 #define DOP_PWM_FROM_ML_PER_MIN(rate)           ( ( ( rate ) * 0.0009F ) + 0.0972F + DOP_PWM_ZERO_OFFSET )
 /// Conversion from PWM duty cycle % to commanded pump motor speed.
-#define DOP_PWM_TO_MOTOR_SPEED_RPM(pwm,dir)     ( ( ( ( pwm ) - DOP_PWM_ZERO_OFFSET) * 4000.0F ) * ( dir == MOTOR_DIR_FORWARD ? 1.0F : -1.0F ) )
+#define DOP_PWM_TO_MOTOR_SPEED_RPM(pwm,dir)     ( ( ( ( pwm ) - DOP_PWM_ZERO_OFFSET) * DOP_100_PCT_PWM_RPM_RANGE ) * ( dir == MOTOR_DIR_FORWARD ? 1.0F : -1.0F ) )
 /// Conversion from RPM to PWM duty cycle %.
-#define DOP_MOTOR_SPEED_RPM_TO_PWM(rpm)         ( ( (F32)(rpm) / 4000.0F ) + DOP_PWM_ZERO_OFFSET )
+#define DOP_MOTOR_SPEED_RPM_TO_PWM(rpm)         ( ( (F32)(rpm) / DOP_100_PCT_PWM_RPM_RANGE ) + DOP_PWM_ZERO_OFFSET )
 /// Macro converts a PWM to an estimated flow rate.
 #define DOP_ML_PER_MIN_FROM_PWM(pwm)            ( ( ( pwm - DOP_PWM_ZERO_OFFSET ) - 0.0972F ) / 0.0009F  )