Electronics International FP-5L - Manual (Page 21)

Power-Up Programmable Settings: Power-Up Programmable Settings: Power-Up Programmable Settings: Power-Up Programmable Settings: Power-Up Programmable Settings:
The FP-5(L) has nine Power-Up Programmable Settings and the FP-5L has two additional settings. These
programmable settings need to be set only once to configure the instrument to your aircraft, engine and personal
preference. The following settings are available:
1&2. First and Second Full Fuel Levels:
There are two Full Fuel Levels that may be set in the FP-5(L). When adding fuel
to the FP-5(L), the First and Second programmed Full Fuel Levels may be retrieved
automatically. The First Full Fuel Level will be displayed with a bar in the upper left
corner of the display. The Second Full Fuel Level will be displayed with a bar in the
lower left corner of the display.
3. K Factor:
The K Factor represents the number of electrical pulses per gallon the FP-5(L) receives from the flow
transducer. Changing the K Factor changes the accuracy of the FP-5(L). Initially, the K Factor should be
set to the value listed for the specific flow transducer. If the flow transducer came from the factory as a package,
the proper K Factor would have been set in the instrument.
Example: Value listed 68,000 (68,000 pulses per gallon measured on the
bench). Set the K Factor on the FP-5(L) for the first three digits of
the K Factor listed (680).
The differences between the elbows, fittings, pipe sizes, hoses and routing methods used during installation
and the fuel pressure for your aircraft can, for any fuel flow gauge, cause the flow transducer to output a
different number of electrical pulses per gallon (K Factor) than when it was tested on the bench. To correct
for any errors in the K Factor, keep track of the Actual Fuel Used (fuel required to bring the tanks back to
full) and compare this with the FP-5(L) Fuel Used (Full Tank Level minus Fuel Remaining as displayed on the
FP-5(L)). If your error is less than 3 gallons for a single tank, you should average the error over 3 tanks of
fuel. Use the following formula to correct the K Factor:
Note: The K Factor can be automatically corrected by using the "Auto Calibrate" Mode (see the Display
Modes and Operation Features section of this manual).
Note: When refueling an aircraft fuel tank, it is not easy to fill the tanks to exactly the same level each time.
Some variables are: 1. How level the wings are during refueling. 2. The affects of any crossover tubes.
19
050
Gal
Blinking Digit
(FP-5(L) Fuel Used) x (Current K Factor)
New K Factor = -----------------------------------------------------
Actual Fuel Used
060
Gal
680
Blinking Digit